JP7200418B2 - semiconductor equipment - Google Patents

Description

One embodiment of the present invention relates to a semiconductor device. One embodiment of the present invention relates to a display device, a display module, and an electronic device.

A technique for forming a transistor (also called a field effect transistor (FET) or a thin film transistor (TFT)) using a semiconductor layer formed over a substrate having an insulating surface has attracted attention. The transistor is widely applied to electronic devices such as integrated circuits (ICs) and image display devices (display devices). A semiconductor material typified by silicon is widely known as a semiconductor layer that can be applied to a transistor, but a technique using an oxide semiconductor as another material is attracting attention.

For example, a technique for manufacturing a transistor using an amorphous oxide containing In, Zn, Ga, Sn, or the like as an oxide semiconductor has been disclosed (see Patent Document 1). Further, a technique for manufacturing a transistor including an oxide semiconductor layer having a self-aligned top-gate structure is disclosed (see Patent Document 2). Further, in order to increase field-effect mobility, a technique for manufacturing a transistor in which an oxide semiconductor layer in which a channel is formed by electric fields of upper and lower gate electrodes is electrically surrounded is disclosed (see Patent Document 3).

In addition, an insulating layer that releases oxygen when heated is used as a base insulating layer of an oxide semiconductor layer that forms a channel, and oxygen vacancies in the oxide semiconductor layer are reduced, whereby a shift in threshold voltage is small during long-term use. A technique for manufacturing a transistor with improved electrical reliability is disclosed (see Patent Document 4).

JP 2006-165529 A JP 2009-278115 A JP 2014-241404 A JP 2012-009836 A

A transistor including an oxide semiconductor layer is expected to be applied to a display device. A capacitive element that constitutes a pixel circuit of a display device has a small area and a large capacitance (hereinafter referred to as a capacitor).
is required. When the capacity for holding the data voltage becomes small, charge injection and feedthrough occur.
This is to avoid the problem of increasing the influence of gh).

In order to obtain a large capacitance in a small area, a capacitor is formed by sandwiching a thin gate insulating film between a gate electrode and a semiconductor layer.
uctor) capacity (or MIS (Metal-Isulator-Semicond
uctor) capacity) is valid. However, the MOS capacitor has a small capacity when holding a low voltage near 0 V, and it is difficult to hold a low-gradation data voltage.

An object of one embodiment of the present invention is to provide a display device or the like with a novel structure in which a large capacity can be obtained even with a small area. Another object of one embodiment of the present invention is to provide a display device or the like with a novel structure in which large capacitance can be obtained even when grayscale display is performed while holding a low voltage.

Note that the problem of one embodiment of the present invention is not limited to the problems listed above. The issues listed above do not preclude the existence of other issues. Still other issues are issues not mentioned in this section, which will be described in the following description. Problems not mentioned in this section can be derived from the descriptions in the specification, drawings, or the like by those skilled in the art, and can be appropriately extracted from these descriptions. One aspect of the present invention is to solve at least one of the above-described problems and/or other problems.

One embodiment of the present invention includes a pixel including a first wiring, a first transistor, a first capacitor, and a light-emitting element, and the first wiring is used to flow current to the light-emitting element. The first transistor includes a first gate electrode, a first insulating layer over the first gate electrode, an oxide semiconductor layer over the first insulating layer, a source electrode and a drain electrode on an oxide semiconductor layer, a second insulating layer on the source electrode, the drain electrode, and the oxide semiconductor layer;
and a second gate electrode on the second insulating layer, and the first capacitive element includes the first electrode and the second gate electrode.
and an insulating layer provided in the same layer as the second insulating layer between the first electrode and the second electrode, wherein the first electrode is the same as the second gate electrode The second electrode has an oxide semiconductor layer provided in the same layer as the oxide semiconductor layer, and the first capacitor has the same layer as the first insulating layer. The display has a third electrode layer electrically connected to the first wiring through an insulating layer provided in the layer, and the third electrode layer is provided in the same layer as the first gate electrode. It is a device.

In one aspect of the present invention, the second gate electrode and the first electrode are oxygen, In, Z
Display devices having n and M, where M is Al, Ga, Y, or Sn, are preferred.

In one embodiment of the present invention, a display device in which the second gate electrode and the first electrode preferably have a higher carrier density than the oxide semiconductor and the second electrode.

In one embodiment of the present invention, the thickness of the second insulating layer is preferably larger than that of the first insulating layer in the display device.

In one embodiment of the present invention, a pixel includes a second transistor, a second capacitor, and a liquid crystal element, the liquid crystal element includes a reflective electrode provided with an opening, and the light emitting element emits light. area is
A display device having a region that overlaps with the region provided with the opening is preferred.

Note that another aspect of the present invention is described in the description and drawings in the following embodiments.

One embodiment of the present invention can provide a display device or the like with a novel structure in which a large capacity can be obtained even with a small area. Alternatively, one embodiment of the present invention can provide a display device or the like with a novel structure in which a large capacity can be obtained even when grayscale display is performed while a low voltage is maintained.

1A and 1B are a circuit diagram and timing charts for explaining a display device of one embodiment of the present invention; 3A and 3B are cross-sectional views and graphs for explaining a display device of one embodiment of the present invention; 1A and 1B are a top view and a cross-sectional view illustrating a display device of one embodiment of the present invention; 1A and 1B are a cross-sectional view and a circuit diagram illustrating a display device of one embodiment of the present invention; FIG. 10 is a circuit diagram illustrating a display device of one embodiment of the present invention; FIG. 10 is a circuit diagram illustrating a display device of one embodiment of the present invention; FIG. 10 is a top view illustrating a display device of one embodiment of the present invention; 1A and 1B are schematic diagrams for explaining a display device of one embodiment of the present invention; 1A and 1B are cross-sectional views illustrating a display device of one embodiment of the present invention; FIG. 10 is a circuit diagram illustrating a display device of one embodiment of the present invention; FIG. 10 is a circuit diagram illustrating a display device of one embodiment of the present invention; 1A and 1B are a circuit diagram and a schematic cross-sectional view for explaining a display device of one embodiment of the present invention; 1 is a configuration example of a display device according to an embodiment; 1 is a configuration example of a display device according to an embodiment; 1 is a configuration example of a display device according to an embodiment; 1 is a configuration example of a touch panel according to an embodiment; 4A and 4B illustrate a method for manufacturing a display device according to an embodiment; 4A and 4B illustrate a method for manufacturing a display device according to an embodiment; 4A and 4B illustrate a method for manufacturing a display device according to an embodiment; 4A and 4B illustrate a method for manufacturing a display device according to an embodiment; 4A and 4B illustrate a method for manufacturing a display device according to an embodiment; An electronic device according to an embodiment. An electronic device according to an embodiment. An electronic device according to an embodiment. An electronic device according to an embodiment. An electronic device according to an embodiment.

Embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and those skilled in the art will easily understand that various changes can be made in form and detail without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the descriptions of the embodiments shown below.

In the configuration of the invention to be described below, the same reference numerals are used in common for the same parts or parts having similar functions in different drawings, and repeated description thereof will be omitted. Moreover, when referring to similar functions, the same hatching pattern may be used and no particular reference numerals may be attached.

In each drawing described in this specification, the size, layer thickness, or region of each configuration is
May be exaggerated for clarity. Therefore, it is not necessarily limited to that scale.

Note that ordinal numbers such as “first” and “second” in this specification and the like are used to avoid confusion of constituent elements, and are not numerically limited.

A transistor is a type of semiconductor element, and can achieve current or voltage amplification, switching operation for controlling conduction or non-conduction, and the like. A transistor in this specification is an IGFET (Insulated Gate Field Effect Trans
Itor) and thin film transistors (TFT: Thin Film Transistor
)including.

Also, the functions of "source" and "drain" may be interchanged when using transistors of different polarities or when the direction of current changes in circuit operation. Therefore, in this specification, the terms "source" and "drain" can be used interchangeably.

(Embodiment 1)
In this embodiment, a structural example of a display device of one embodiment of the present invention will be described.

[Configuration example of circuit diagram]
FIG. 1A is a circuit diagram of a pixel included in a display device.

The pixel PIX has a transistor M1, a transistor M2, a transistor M3, a capacitive element MC, and a light emitting element EL. The pixels PIX are connected to a scanning line GL, a signal line SL, a current supply line ANODE, a wiring V0, and a common wiring CATHODE. A pixel PIX corresponds to a sub-pixel included in a pixel for color display. Note that transistors M1, M2 and M3
will be described below as an n-channel transistor, but may be a p-channel transistor.

A scanning line GL is a wiring for supplying a scanning signal to a pixel. The scanning signal is a signal that controls the conduction state of the supplied transistor. A signal line SL is a wiring for supplying a data voltage corresponding to image data to pixels. A current supply line ANODE and a common wiring CATHODE are wirings for supplying a current to the light emitting element EL. The wiring V0 is a wiring to which a constant voltage is applied.

The capacitor MC is a capacitor including a transistor in which gate electrodes are provided above and below an oxide semiconductor layer. A gate electrode formed of a metal material located below the oxide semiconductor layer of the capacitor MC is referred to as a first gate electrode (also referred to as a bottom gate electrode). A gate electrode formed using a metal oxide material over the oxide semiconductor layer is referred to as a second gate electrode (also referred to as a top gate electrode). Note that a metal oxide material is a material containing a metal element and oxygen.

The capacitive element MC is a so-called MOS capacitor including a second gate electrode, an insulating layer provided in contact with the second electrode, and an oxide semiconductor layer. A second gate electrode, which is one electrode of the capacitive element MC, is connected to the gate electrode of the transistor M3. A source electrode and a drain electrode, which are the other electrodes of the capacitive element MC, are connected to the source electrode of the transistor M3. The first gate electrode is connected to the current supply line ANODE, in other words, the other of the source and drain of the transistor M3.

Note that although the transistors M1, M2, and M3 are illustrated as single-gate transistors, they may have a structure in which gate electrodes are provided above and below an oxide semiconductor layer, similarly to the capacitor MC. Configuration examples applicable to the capacitive element MC and the transistors M1, M2 and M3 will be described later.

A gate electrode of the transistor M1 is connected to the scanning line GL. One of the source and the drain of transistor M1 is connected to signal line SL. The other of the source and drain of the transistor M1 is connected to the gate electrode of the transistor M3 and one electrode of the capacitive element MC.

A gate electrode of the transistor M2 is connected to the scanning line GL. One of the source and drain of the transistor M2 is connected to the wiring V0. The other of the source and drain of the transistor M2 is connected to one of the source and drain of the transistor M3, the other electrode of the capacitor MC, and one electrode of the light emitting element EL.

the gate electrode of transistor M3 is the other of the source or drain of transistor M1;
and one electrode of the capacitive element MC. One of the source and drain of the transistor M3 is connected to the other of the source and drain of the transistor M2, the other electrode of the capacitor MC, and one electrode of the light emitting element EL. The other of the source and drain of the transistor M3 is connected to the current supply line ANODE.

One electrode of the light-emitting element EL is connected to the other of the source or drain of the transistor M2, one of the source or drain of the transistor M3, and the other electrode of the capacitor MC. The other electrode of the light emitting element EL is connected to a common wiring CATHODE.

FIG. 1B shows a timing chart for explaining the simple operation of FIG. 1A. FIG. 1B shows one scanning selection period (P _SCAN ) for the m-th scanning line GL_m. Also shown are the voltage V _ANODE applied to the current supply line ANODE, the voltage of the wiring V0, and the image signal of the signal line SL.

As shown in FIG. 1B, the image signal of the signal line SL in one scanning selection period is (m−1)
The signal DATA_m−1 in the row is switched to the signal DATA_m in the mth row. During this time, the voltage V _ANODE applied to the current supply line ANODE is applied to the wiring V ANODE in order to cause a current to flow through the light emitting element EL.
A voltage higher than that of O is set.

In the structures of FIGS. 1A and 1B, the first gate electrode is formed using a conductive layer made of a metal material, and the second gate electrode is formed using a conductive layer made of a metal oxide material. can. A conductive layer formed using a metal oxide material can supply oxygen to an insulating layer, which is a film formation surface, during film formation. The insulating layer to which oxygen is supplied can be released to the semiconductor layer including the oxide semiconductor by heating. Therefore, by using a conductive layer made of a metal oxide material for the second gate electrode, the reliability of the transistors M1, M2, and M3 can be improved.

In the structures of FIGS. 1A and 1B, the shift in threshold voltage is reduced by reducing the reliability of the transistors M1, M2, and M3, that is, oxygen vacancies in the semiconductor layer including an oxide semiconductor, as described above. be able to. On the other hand, when a transistor functions as a MOS capacitor and the threshold voltage of the transistor is around 0 V, the capacity is small when holding a low voltage, making it difficult to hold a low-gradation data voltage.

In FIG. 2A, the voltages of the first gate electrode, the second gate electrode, and the electrodes functioning as the source and drain of the transistor functioning as the MOS capacitor shown in the circuit diagram are represented by "Vb" and "Vg", respectively. , and “Vs”. In FIG. 2B, the horizontal axis is the voltage "Vg-Vs" between the second gate electrode and the source electrode, and the capacitive element MC, which is a MOS capacitor, is plotted.
is a graph in which the vertical axis is the capacity of

As shown in FIG. 2B, M
In the case of an OS capacitor, when Vb applied to the first gate electrode and Vb applied to the source electrode are at the same potential (Vb−Vs=0), when a low voltage is applied to the second gate electrode, the holding capacity is small. .

On the other hand, as shown in FIG. 2B, even when a transistor whose threshold voltage is close to 0 V is used as a MOS capacitor, Vb applied to the first gate electrode is larger than Vb applied to the source electrode. (Vb−Vs>0), the threshold voltage of the transistor can be negatively shifted. Specifically, as shown in FIGS. 1A and 1B, the wiring VO
The voltage V _ANODE applied to the current supply line ANODE, which is higher than the voltage of , functions as Vb applied to the first gate electrode. Therefore, even when a low voltage is applied to the second gate electrode, the holding capacity can be increased.

In the structures of FIGS. 1A and 1B, the insulating layer between the second gate electrode and the oxide semiconductor layer releases oxygen by heating to reduce oxygen vacancies in the oxide semiconductor layer. Therefore, the insulating layer is thinner than the insulating layer between the first gate electrode and the oxide semiconductor layer. Therefore, the capacitive element MC can have a large capacitance with a small area.

Note that although the transistors M1, M2, and M3 have a single gate structure in FIG. 1A, they have a first gate electrode and a second gate electrode like the pixel PIX_A shown in FIG. , the gate electrodes may be connected to each other. In this structure, the transistors M1, M2, and M3 have a structure in which gate electrodes are provided above and below an oxide semiconductor layer, similarly to the capacitor MC.

In FIG. 1A, the first gate electrode of the capacitor MC is connected to the current supply line ANODE. configuration may be used. For example, as in the pixel PIX_B shown in FIG. 3B, the first gate electrode may be connected to a wiring V1 different from the current supply line ANODE. As with the current supply line ANODE, it is preferable to apply a higher voltage to the wiring V1 than the voltage applied to the wiring V0.

Although two gate electrodes of the transistors M1, M2, and M3 are connected in FIG. 2A, different signals may be applied to the first gate electrode and the second gate electrode. For example, as in the pixel PIX_C illustrated in FIG. 4A, the first gate electrodes of the transistors M1 and M2 may be connected to the scan line GL, and the second gate electrodes thereof may be connected to the wiring V0. With this configuration, in the transistors M1 and M2, the first
A scanning line GL made of a metal material can be arranged in the same layer as the gate electrode. Therefore, even if a configuration in which the first gate electrode is formed of a conductive layer made of a metal material and the second gate electrode is formed of a conductive layer made of a metal oxide material, the scanning line GL It is possible to avoid the problem that the resistance of the In addition, the manufacturing cost can be reduced by providing an extra wiring made of a metal material in order to lower the resistance of the scanning line GL.

Note that FIG. 2A shows a structure in which the current supply line ANODE is arranged in a direction parallel to the signal line SL and the wiring V0, but other structures may be used. For example, the pixel PI shown in FIG.
As in X_D, the current supply line ANODE may be arranged in a direction parallel to the scanning line GL.

[Transistor configuration example]
Here, configuration examples of transistors or MOS capacitors applicable to the transistors M1, M2, and M3 and the capacitive element MC will be described with reference to FIGS.

5A, 5B, and 5C illustrate an example of a semiconductor device including a transistor. Figure 5
The transistors shown in (A), (B), and (C) have structures in which gate electrodes are provided above and below a semiconductor layer.

5A is a top view of the transistor 100, FIG. 5B is a cross-sectional view taken along dashed-dotted line X1-X2 in FIG. 5A, and FIG. 5C is FIG. 2 is a cross-sectional view between one-dot chain line Y1-Y2 of FIG. Note that in FIG. 5A, constituent elements such as the insulating layer 110 are omitted for clarity. Note that in the top view of the transistor, FIG. 5 (
As in A), some of the constituent elements may be omitted in the illustration. In addition, the dashed-dotted line X1-X
The two directions are sometimes called the channel length (L) direction, and the one-dot chain line Y1-Y2 direction is sometimes called the channel width (W) direction.

A transistor 100 illustrated in FIGS. 5A, 5B, and 5C includes a conductive layer 106 formed over a substrate 102, an insulating layer 104 over the conductive layer 106, and an oxide semiconductor layer 108 over the insulating layer 104.
an insulating layer 110 over the oxide semiconductor layer 108, a metal oxide layer 112 over the insulating layer 110, an insulating layer 116 over the insulating layer 104, the oxide semiconductor layer 108, and the metal oxide layer 112;
have In addition, the oxide semiconductor layer 108 has a channel region 108 i in contact with the insulating layer 110 .
, a source region 108s in contact with the insulating layer 116, and a drain region 1 in contact with the insulating layer 116.
08d.

In the transistor 100, the conductive layer 120a is electrically connected to the source region 108s through the opening 141a provided in the insulating layer 116, and the drain region 108d is connected through the opening 141b provided in the insulating layer 116. and a conductive layer 120b electrically connected to the .

Note that the conductive layer 106 functions as a first gate electrode and is made of a metal material. The metal oxide layer 112 functions as a second gate electrode and is made of a metal oxide material. In addition, the insulating layer 104 functions as a first gate insulating layer, and the insulating layer 110
functions as a second gate insulating layer.

Further, the insulating layer 116 contains one or both of nitrogen and hydrogen. insulating layer 1
16 contains either or both of nitrogen and hydrogen, either or both of nitrogen and hydrogen can be supplied to the oxide semiconductor layer 108 and the metal oxide layer 112 .

The insulating layer 116 may be, for example, a nitride insulating layer. The nitride insulating layer can be formed using silicon nitride, silicon nitride oxide, aluminum nitride, aluminum nitride oxide, or the like. The concentration of hydrogen contained in the insulating layer 116 is 1×10 ²² atoms.
/cm ³ or more.

In addition, the metal oxide layer 112 has a function of supplying oxygen to the insulating layer 110 . Since the metal oxide layer 112 has a function of supplying oxygen to the insulating layer 110, the insulating layer 110 can contain excess oxygen. Since the insulating layer 110 has the excess oxygen region, the excess oxygen can be supplied to the oxide semiconductor layer 108, more specifically, the channel region 108i. Therefore, a highly reliable semiconductor device can be provided.

The insulating layer 110 can be formed using a single layer or stacked layers of an oxide insulating layer or a nitride insulating layer. As the insulating layer 110, for example, silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, aluminum oxide, hafnium oxide, gallium oxide, or G
An a-Zn oxide or the like may be used, and it can be provided as a single layer or a stacked layer.

When the insulating layer 110 formed over the oxide semiconductor layer 108 contains excess oxygen, excess oxygen can be selectively supplied only to the channel region 108i.
Alternatively, after supplying excess oxygen to the channel region 108i, the source region 108s and the drain region 108d, the carrier densities of the source region 108s and the drain region 108d may be selectively increased.

The carrier density of the metal oxide layer 112 is increased by supplying one or both of nitrogen and hydrogen from the insulating layer 116 . In other words, the metal oxide layer 112 also functions as an oxide conductor (OC). Therefore, the metal oxide layer 112 has a higher carrier density than the oxide semiconductor layer 108 .

The source region 108s and the drain region 108d included in the oxide semiconductor layer 108 and the metal oxide layer 112 may each contain an element that forms oxygen vacancies. Elements that form the oxygen vacancies are typically hydrogen, boron, carbon, nitrogen, fluorine, phosphorus, sulfur, chlorine, rare gases, and the like. Representative examples of rare gas elements include helium,
Examples include neon, argon, krypton, and xenon.

When the impurity element is added to the oxide semiconductor layer, the bond between the metal element and oxygen in the oxide semiconductor layer is broken, and oxygen vacancies are formed. Alternatively, when an impurity element is added to the oxide semiconductor layer, oxygen that has been bonded to the metal element in the oxide semiconductor layer bonds to the impurity element, oxygen is released from the metal element, and oxygen vacancies are formed. be. As a result, the oxide semiconductor layer has an increased carrier density and high conductivity.

In the transistor 100, it is preferable that side edges of the insulating layer 110 and side edges of the metal oxide layer 112 have aligned regions. In other words, in the transistor 100, the upper end portion of the insulating layer 110 and the lower end portion of the metal oxide layer 112 are substantially aligned. For example, the above structure can be obtained by processing the insulating layer 110 using the metal oxide layer 112 as a mask.

The oxide semiconductor layer 108 and the metal oxide layer 112 are made of In--M--Zn oxide (M is Al,
It is formed of an oxide semiconductor such as Ga, Y, or Sn). Alternatively, for the oxide semiconductor layer 108 and the metal oxide layer 112, an In--Ga oxide or an In--Zn oxide may be used. In particular, it is preferable that the oxide semiconductor layer 108 and the metal oxide layer 112 be formed using an oxide semiconductor containing the same constituent element, because manufacturing cost can be reduced.

In the case where the oxide semiconductor layer 108 and the metal oxide layer 112 are In--M--Zn oxide, In
The atomic ratio of the metal elements in the sputtering target used for forming the -M-Zn oxide preferably satisfies In≧M and Zn≧M. The atomic ratios of metal elements in such a sputtering target are In:M:Zn=1:1:1 and In:M:Zn=1:1.
: 1.2, In:M:Zn=2:1:1.5, In:M:Zn=2:1:2.3, In:
M:Zn=2:1:3, In:M:Zn=3:1:2, In:M:Zn=4:2:4.1
, In:M:Zn=5:1:7, and the like. Note that the oxide semiconductor layer 108 to be deposited,
and the metal oxide layer 112 may vary by plus or minus 40% of the atomic ratio of the metal elements contained in the sputtering target. For example, when a sputtering target with an atomic ratio of In:Ga:Zn=4:2:4.1 is used, the atomic ratio of the deposited oxide semiconductor layer is In:Ga:Zn=4:2. : 3 in some cases.

By using an oxide semiconductor layer with a low impurity concentration and a low defect level density for the channel region 108i, a transistor with even better electrical characteristics can be manufactured.
Here, a low impurity concentration and a low defect level density (few oxygen vacancies) are referred to as high-purity intrinsic or substantially high-purity intrinsic. Alternatively, it is called authentic or substantially authentic. A highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor has few carrier generation sources,
In some cases, the carrier density can be lowered. Therefore, a transistor whose channel region is formed in the oxide semiconductor layer tends to have electrical characteristics in which the threshold voltage is positive (also referred to as normally-off characteristics). Further, since a highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor layer has a low defect level density, the trap level density may also be low.
In addition, a highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor layer can have extremely low off-state current. Therefore, a transistor in which a channel region is formed in the oxide semiconductor layer may be a highly reliable transistor with small variations in electrical characteristics.

Meanwhile, the source region 108s, the drain region 108d, and the metal oxide layer 112 are in contact with the insulating layer 116 . source region 108s, drain region 108d, and metal oxide layer 1
12 is in contact with the insulating layer 116, one or both of hydrogen and nitrogen are added from the insulating layer 116 to the source region 108s, the drain region 108d, and the metal oxide layer 112, so that the carrier density increases.

The carrier density of the oxide semiconductor layer is described below.

Factors that affect the carrier density of the oxide semiconductor layer include oxygen vacancies (Vo) in the oxide semiconductor layer, impurities in the oxide semiconductor layer, and the like.

When oxygen vacancies in the oxide semiconductor layer increase, hydrogen bonds to the _oxygen vacancies (this state is referred to as VO
H), the defect level density increases. Alternatively, when the number of impurities in the oxide semiconductor layer increases, the density of defect states increases due to the impurities. Therefore, the carrier density of the oxide semiconductor layer can be controlled by controlling the defect level density in the oxide semiconductor layer.

As shown in FIG. 5C, the oxide semiconductor layer 108 faces the conductive layer 106 functioning as the first gate electrode and the metal oxide layer 112 functioning as the second gate electrode. It is sandwiched between two conductive layers or oxide semiconductor layers that function as gate electrodes.

With the structure in FIG. 5C, when the transistor 100 functions as a transistor, the oxide semiconductor layer 108 included in the transistor 100 is subjected to an electric field generated by a scanning signal of the conductive layer 106 functioning as a first gate electrode. , and a constant voltage electric field in the metal oxide layer 112, which serves as the second gate electrode.

Although not shown in FIG. 5C, the transistor 100 has openings provided in the insulating layers 110 and 104 for connecting the first gate electrode and the second gate electrode. may be configured. With such a structure, the oxide semiconductor layer 108 included in the transistor 100 is combined with the conductive layer 106 functioning as a first gate electrode and the second gate electrode.
The metal oxide layer 112, which functions as the gate electrode of the , can be electrically surrounded by electric fields on both sides.

Further, with the structure in FIG. 5C, in the case where the transistor 100 functions as a MOS capacitor, a voltage that negatively shifts the threshold voltage of the transistor can be applied to the conductive layer 106 functioning as a first gate electrode. . A MOS capacitor can be formed by the oxide semiconductor layer 108, the insulating layer 110, and the metal oxide layer 112 functioning as a second gate electrode.

When the transistor 100 functions as a MOS capacitor, a capacitor can be formed using the oxide semiconductor layer 108, the insulating layer 110, and the metal oxide layer 112 illustrated in the cross-sectional view of FIG. That is, a MOS capacitor corresponding to the capacitive element MC in the circuit diagram of FIG. 5B can be formed. Note that in FIGS. 6A and 6B, "Vg", "Vs", and "V
b" represents the corresponding voltage in the circuit diagram and cross-sectional view, as in FIG. 2(A).

6A and 6B, the voltage Vg applied to the conductive layer 106 is a voltage that negatively shifts the threshold voltage of the transistor. Insulating layer 110 forming a MOS capacitor
is smaller than the thickness 104t of the insulating layer 104 . Therefore, even when a small voltage is applied to the metal oxide layer 112 and a capacitance is formed with the metal oxide layer 112 with the insulating layer 110 interposed therebetween, a high capacitance can be ensured and a small area can be used. It can have a large capacity.

[Configuration example of top view]
Next, FIG. 7 shows an example of a top view applicable to the circuit configuration of the pixel PIX_D in FIG. 4B, excluding the configuration of light emitting elements and the like. FIG. 8 illustrates how the conductive layers, semiconductor layers, and the like, which are in a vertical relationship in the top view of FIG. 7, are divided into layers and connected through openings.
9A is a cross-sectional view taken along dotted line P1-P2 in FIG. 7, and FIG. 9B is a cross-sectional view taken along dotted line Q1-Q2 in FIG. FIG. 10 is a circuit diagram showing a plurality of pixels arranged corresponding to the arrangement of the transistors in the top view of FIG.

In the top view of FIG. 7, the scanning line GL, the signal line SL, the wiring V0, and the current supply line ANODE
, a transistor M1, a transistor M2, a transistor M3, a capacitive element MC,
is illustrated. In the layer structure of the conductive layer, the metal oxide layer, and the oxide semiconductor layer, illustration of an insulating layer and the like is omitted.

The layer structures of the conductive layer, the metal oxide layer, and the oxide semiconductor layer forming each wiring and the like in FIG. 7 can be understood from FIGS. 8 and 9. FIG. A conductive layer 151, a conductive layer 152, and a conductive layer 153 functioning as a first gate electrode are provided on the substrate SUB. Next, an oxide semiconductor layer 161 and an oxide semiconductor layer 162 are provided with an insulating layer 154 functioning as a first gate insulating layer provided therebetween. Next, an insulating layer 163 functioning as a second gate insulating layer
A metal oxide layer 171 , a metal oxide layer 172 , and a metal oxide layer 173 functioning as a second gate electrode are provided through the . Next, the carrier densities in part of the oxide semiconductor layer 161, part of the oxide semiconductor layer 162, and the metal oxide layer 171, the metal oxide layer 172, and the metal oxide layer 173 are selectively increased to make it conductive. A conductive layer 181, a conductive layer 182, a conductive layer 183, a conductive layer 184, and a conductive layer 185 functioning as a source electrode, a drain electrode, or various wirings of a transistor are provided through an insulating layer 174 that increases the voltage. Next, an insulating layer 186, an insulating layer 187, and an insulating layer 18 functioning as interlayer insulating layers are formed.
8 is provided. In addition, the insulating layer 186, the insulating layer 187 and the insulating layer 188 are provided with a conductive layer 1
An opening 190 is provided that reaches 85 . This opening 190 is an opening for forming a pixel electrode and connecting it to a light emitting element provided thereon.

In FIGS. 7 and 8, squares marked with crosses represent openings formed in the insulating layer. Through the openings, the conductive layer, metal oxide layer, and oxide semiconductor layer of each layer are connected as indicated by arrows in FIG. In addition, in FIG. 8, the conductive layer 151 that becomes the scanning line GL,
Conductive layer 152 to be NODE, conductive layer 181 to be wiring V0, conductive layer 1 to be signal line SL
82 is shown.

As can be seen from FIGS. 7, 8 and 9, in the transistors M1, M2 and M3, the first gate electrode and the second gate electrode are connected. With this structure, the amount of current that flows through the transistor can be increased compared to the case where the gate electrodes are not connected to each other.

Further, as can be seen from FIGS. 7, 8 and 9, the current supply line ANODE is provided below the metal oxide layer 171, the insulating layer 163 and the oxide semiconductor layer 161 forming the capacitive element MC.
A conductive layer 152 connected to . In this structure, the voltage of the current supply line ANODE applied to the conductive layer 152 negatively shifts the threshold voltage of the transistor, and the thickness of the insulating layer 163 is smaller than that of the insulating layer 154, so that high capacitance can be ensured. Therefore, a large capacity can be obtained with a small area.

Note that the conductive layer 152 connected to the current supply line ANODE and the conductive layer 151 to be the scanning line GL
has a function as a light shielding layer by being composed of a metal material having light shielding properties and conductivity. Therefore, variations in electrical characteristics of the MOS capacitance and the transistor can be reduced.

10 shows a circuit diagram of 2×2 pixels PIX_ corresponding to the top view of the pixels described in FIG.
FIG. 2 is a circuit diagram illustrated as UL, pixel PIX_UR, pixel PIX_LL and pixel PIX_LR; In FIG. 10, pixels arranged in two rows of m row and (m+1 row), n column, and (n+1) column are illustrated. In FIG. 10 , the m-th scanning line GL_m, the (m+1)-th scanning line GL_m+1, the n-th signal line SL_n, the (n+1)-th signal line SL_n+1, the wiring V0, the current supply The lines ANODE and .

As shown in FIG. 10, the pixel PIX_UL and the pixel PIX_UR have a configuration in which the transistors M1, M2, M3 and the capacitive element MC, which form the pixel with the wiring V0 interposed therebetween, are line-symmetrically arranged and connected to the same wiring V0. . Pixel PIX_LL and pixel PIX_LR also include transistors M1, M2, and M3 and capacitive element MC
are arranged line-symmetrically and connected to the same wiring V0.

Further, as illustrated in FIG. 10, the pixel PIX_UL and the pixel PIX_LL include transistors M1, M2, and M3 and a capacitive element MC
are arranged line-symmetrically and connected to the same current supply line ANODE. Also, the pixel PIX_
Similarly, in the UR and the pixel PIX_LR, the transistors M1, M2, M3 and the capacitive element MC forming the pixel with the current supply line ANODE interposed therebetween are arranged line-symmetrically, and the same current supply line AN
It is configured to be connected to ODE.

By arranging elements, wirings, and the like shown in FIG. 10, the number of wirings and the like arranged between pixels for connection to each pixel can be reduced. The configuration of FIG. 10 is preferable because the area of the pixel can be reduced by reducing the number of wirings and the like when designing to increase the definition of the pixel.

[Modification]
A circuit structure that can be applied to one embodiment of the present invention is the transistors M1 and M2 in FIG.
and M3. For example, a pixel configuration having two or less transistors as shown in FIG. 11A is also applicable.

The pixel configuration of the pixel PIX_E illustrated in FIG. 11A includes a transistor M1, a transistor M3, a capacitor MC, and a light emitting element EL. That is, it corresponds to the circuit configuration in which the transistor M2 is omitted in FIG.

Also in the configuration shown in FIG. 11A, the voltage of the current supply line ANODE is applied to the first gate electrode of the capacitive element MC in which the transistor functions as the MOS capacitor. Then, when a voltage that negatively shifts the threshold voltage of the transistor is applied, and a low voltage is applied to the MOS capacitor composed of the metal oxide layer which is the second gate electrode, the insulating layer, and the oxide semiconductor layer, capacity can be increased. The insulating layer between the second gate electrode and the oxide semiconductor layer is thinner than the insulating layer between the first gate electrode and the oxide semiconductor layer, so that high capacitance can be secured; It can have a large capacity.

A circuit structure that can be applied to one embodiment of the present invention is not limited to the pixel structure in FIG.
For example, a pixel configuration having four or more transistors as shown in FIG. 11B is also applicable.

The pixel configuration of the pixel PIX_F shown in FIG. 11A includes a transistor M1, a transistor M2, a transistor M3, a transistor M4, a transistor M5, and a capacitive element MC
and a light emitting element EL. The pixel configuration includes a signal line SL, a current supply line ANOD
E, wiring V0, common wiring CATHODE, and scanning lines GL1, GL2 and GL3 operate.

Also in the configuration shown in FIG. 11B, the voltage of the current supply line ANODE is applied to the first gate electrode of the capacitive element MC in which the transistor functions as the MOS capacitor. Then, when a voltage that negatively shifts the threshold voltage of the transistor is applied, and a low voltage is applied to the MOS capacitor composed of the metal oxide layer which is the second gate electrode, the insulating layer, and the oxide semiconductor layer, capacity can be increased. The insulating layer between the second gate electrode and the oxide semiconductor layer is thinner than the insulating layer between the first gate electrode and the oxide semiconductor layer, so that high capacitance can be secured; It can have a large capacity.

Further, a circuit structure that can be applied to one embodiment of the present invention is not limited to a pixel structure including a light-emitting element, and can be applied to a pixel including a liquid crystal element and a light-emitting element.

The pixel configuration of the pixel PIX_G shown in FIG. 12A as an example includes a transistor M1, a transistor M2, a transistor M3, a capacitive element MC, a transistor M6, a capacitive element MC1, and a liquid crystal element LC. have. Further, the pixel configuration includes signal lines SL_LC,
Signal line SL_EL, current supply line ANODE, wiring V0, scanning line GL_EL, scanning line GL_
LC, operated by common wiring CATHODE.

In the pixel PIX_G, the video signal applied to the gate electrode of the transistor M3 is applied from the signal line SL_EL by controlling the scanning signal applied to the scanning line GL_EL. Pixel P
In IX_G, the video signal given to one electrode of the liquid crystal element LC is the scanning line GL_LC
is given from the signal line SL_LC by control of the scanning signal given to . That is, the pixel PIX
The gradation display of the liquid crystal element LC and the light emitting element EL can be separately controlled for each _G.
In such a configuration, unlike the control of a backlight in which a plurality of pixels are uniformly lit, it is possible to control the light emission of the light-emitting element EL according to the image to be displayed at the pixel level, which is the minimum unit. Light emission can be suppressed. Therefore, a display device including the pixel PIX_G can consume less power.

Further, in the configuration of the pixel PIX_G, the reflective electrode of the liquid crystal element LC can adjust the intensity of the reflected light using the external light in the liquid crystal layer to perform gradation display. Therefore, the pixel PIX_
A display device having G can improve outdoor visibility.

Further, in the configuration of the pixel PIX_G, gradation display is performed by adjusting the intensity of light emitted from the light emitting element EL. Therefore, a display device having the pixel PIX_G can improve visibility indoors where the intensity of outside light is low.

Note that a configuration in which display is performed outdoors by controlling the liquid crystal element LC or a configuration in which display is performed indoors by controlling the light-emitting element EL may be a configuration in which a sensor capable of measuring illuminance is provided in the display device.

Also in the configuration shown in FIG. 12A, the voltage of the current supply line ANODE is applied to the first gate electrodes of the capacitive elements MC and MC1 in which transistors function as MOS capacitors. Then, when a voltage that negatively shifts the threshold voltage of the transistor is applied, and a low voltage is applied to the MOS capacitor composed of the metal oxide layer which is the second gate electrode, the insulating layer, and the oxide semiconductor layer, capacity can be increased. The insulating layer between the second gate electrode and the oxide semiconductor layer is thinner than the insulating layer between the first gate electrode and the oxide semiconductor layer, so that high capacitance can be secured; It can have a large capacity.

A display device having a pixel PIX_G illustrated in FIG. 12A can include a light-emitting element EL and a liquid crystal element LC overlapping each other as illustrated in the schematic cross-sectional view of FIG. 12B. In FIG. 12B, a layer 191 having a transistor is provided between the light emitting element EL and the liquid crystal element LC. The layer 191 including transistors includes a transistor M1, a transistor M2, a transistor M3, a capacitor MC, a transistor M6, and a capacitor MC1. The liquid crystal element LC in FIG. 12B has an electrode 1 capable of reflecting external light (L _REF ).
has 92. The electrode 192 has an opening 193 for transmitting light (L _EL ) from the light emitting element.
is provided.

In a display device in which the cross-sectional schematic diagram shown in FIG. 12B is applied to the pixel PIX_G described in FIG. be. For example, when the illuminance is high, the liquid crystal element LC is driven to obtain a desired gradation, and when the illuminance is low, the light-emitting element EL is driven to obtain a desired gradation. With such a structure, a display device with low power consumption and excellent visibility can be obtained.

This embodiment can be implemented by appropriately combining at least part of it with other embodiments described herein.

(Embodiment 2)
In this embodiment, a cross-sectional structure example of a display device of one embodiment of the present invention will be described.

[Configuration example of display device]
FIG. 13 shows a schematic top view of the display device 10 described below. The display device 10 includes a pixel portion 11, a scanning line driver circuit 12, a signal line driver circuit 13, a terminal portion 15, a plurality of wirings 16a, a plurality of wirings 16b, and the like.

[Cross-sectional configuration example 1]
FIG. 14 is a schematic cross-sectional view of the display device 10. As shown in FIG. FIG. 14 shows, for example, the cutting line A1 in FIG.
- corresponds to a cross-section along A2.

The display device 10 has a configuration in which a first substrate 201 and a second substrate 202 are bonded together with an adhesive layer 220 .

Over the first substrate 201, a terminal portion 15, a wiring 16b, a transistor 252 forming the signal line driver circuit 13, transistors 251 and 252 forming the pixel portion 11, a capacitor 253, a light emitting element 254, and the like are provided. ing. An insulating layer 211 , an insulating layer 212 , an insulating layer 213 , an insulating layer 214 , a spacer 215 , and the like are provided over the first substrate 201 .

An insulating layer 221 , a light shielding layer 231 and a colored layer 2 are provided on the first substrate 201 side of the second substrate 202 .
32, a structure 230a, a structure 230b, etc. are provided.

A light-emitting element 254 is provided over the insulating layer 213 . The light emitting element 254 has a pixel electrode 225 functioning as a first electrode, an EL layer 222 and a second electrode 223 . An optical adjustment layer 224 is provided between the pixel electrode 225 and the EL layer 222 . insulating layer 214
is provided to cover the edge portions of the pixel electrode 225 and the optical adjustment layer 224 .

The transistor 251 functions as the transistor M1 or M2 described in FIG. 1A of Embodiment 1 above. The transistor 252 is similar to that of the first embodiment described above.
This transistor functions as the transistor M3 described in FIG.

In the transistors 251, 252, and 255, the conductive layer 2 serving as a first gate electrode
75, and a conductive layer 272 that functions as a second gate electrode. That is, it is a structure in which a semiconductor in which a channel is formed is sandwiched between two gate electrodes. Conductive layer 275
corresponds to the conductive layer 106 functioning as the first gate electrode described with reference to FIG. 2 of the first embodiment. The conductive layer 272 corresponds to the metal oxide layer 112 functioning as the second gate electrode described in FIG. 2 of Embodiment 1 above.

By using the conductive layer 275 as an electrode capable of repairing oxygen vacancies in the semiconductor layer 271 by releasing oxygen, the electrical characteristics of the transistor can be stabilized.

In a transistor connected to a light-emitting element like the transistor 252, it is preferable that two gate electrodes be electrically connected so that the same signal is supplied to them. Such a transistor can increase field-effect mobility and increase on-current compared to other transistors. As a result, a circuit capable of high speed operation can be manufactured.

The capacitive element 253 is composed of part of the conductive layer 275, part of the insulating layer 211, and part of the semiconductor layer 271. As shown in FIG. 217 and part of the conductive layer 273 may be used.

FIG. 14 shows an example in which the light emitting element 254 is a top emission structure light emitting element. Light emitted from the light emitting element 254 is emitted to the second substrate 202 side. With such a structure, transistors, capacitive elements,
Since circuits, wirings, and the like can be arranged, the aperture ratio of the pixel portion 11 can be increased.

On the surface of the second substrate 202 on the first substrate 201 side, a colored layer 23 overlapping with the light emitting element 254 is formed.
2 is provided. A light shielding layer 231 may be provided in a portion where the colored layer 232 is not provided. The light shielding layer 231 may be provided at a position overlapping with the signal line driving circuit 13 as shown in FIG. A translucent overcoat layer may be provided to cover the colored layer 232 and the light shielding layer 231 .

On the first substrate 201 side of the second substrate 202, a structure 230a is provided in a region inside the adhesive layer 220, and a structure 230b is provided in a region outside the adhesive layer 220. . The structure 230a and the structure 230b have a function of suppressing cracks from progressing when the insulating layer 221 or the second substrate 202 cracks at the edge of the second substrate 202 . FIG. 14 shows an example in which the structure 230a and the structure 230b have a laminated structure of a layer made of the same film as the light shielding layer 231 and a layer made of the same film as the colored layer 232a. By forming a laminated structure of two or more layers in this manner, the effect of suppressing the progress of cracks can be further enhanced. Here, structures 230 are formed on both sides of the adhesive layer 220 .
a and structure 230b are shown, either one may be suitable. If there is no risk of cracking (for example, if the second substrate 202 or the like has high rigidity), the structures 230a and 230b may not be provided.

A spacer 215 is provided on the insulating layer 214 . The spacer 215 has a function as a gap spacer that controls the distance between the first substrate 201 and the second substrate 202 so that it does not shrink more than necessary. The angle between a part of the side surface of the spacer 215 and the forming surface is preferably 45 degrees or more and 120 degrees or less, more preferably 60 degrees or more and 100 degrees or less, further preferably 75 degrees or more and 90 degrees or less. It is preferred to have a portion that is This facilitates formation of a region where the EL layer 222 is thin on the side surface of the spacer 215 . Therefore, it is possible to suppress a phenomenon in which light is emitted between adjacent light emitting elements when a current flows through the EL layer 222 . In particular, when the pixel portion 11 has a high definition, the distance between adjacent light emitting elements becomes small, so providing the spacer 215 having such a shape between the light emitting elements is effective. Furthermore, it is particularly effective when the EL layer 222 has a layer containing a highly conductive material.

In addition, the spacer 215 functions as a mask gapper that prevents the formation surface from being damaged by the shielding mask when a shielding mask is used for forming the EL layer 222, the second electrode 223, and the like. may

The spacer 215 is preferably provided so as to overlap the wiring crossing the scanning line.

FIG. 14 shows an example of the display device 10 using the color filter method. For example, the colored layer 232 may be configured to express one color by sub-pixels of three colors to which any one of red (R), green (G), and blue (B) is applied. In addition to this, white (W)
It is preferable to use sub-pixels of yellow or yellow (Y) because color reproducibility can be improved and power consumption can be reduced.

In the light emitting element 254 , light with high color purity can be extracted from the display device 10 by combining the microcavity structure of the colored layer 232 and the optical adjustment layer 224 .
The thickness of the optical adjustment layer 224 may be different depending on the color of each sub-pixel. Further, depending on the sub-pixel, a configuration without an optical adjustment layer may be employed.

An EL layer that emits white light is preferably used as the EL layer 222 included in the light-emitting element 254 . By applying such a light-emitting element 254, the EL layer 222 can be formed in each sub-pixel.
Since it is not necessary to separately paint the , the cost can be reduced, the yield can be improved, and the definition of the pixel portion 11 can be easily increased. Further, by providing an optical adjustment layer having a different thickness for each sub-pixel, the EL layer 222 may be separately painted for each sub-pixel. In this case, either the optical adjustment layer or the colored layer , or may be configured without both. At this time, at least the light-emitting layer of the EL layer 222 may be separately painted in each sub-pixel, and the other layers may be formed without being separately painted.

FIG. 14 shows an example in which an FPC 242 electrically connected to the terminal portion 15 is provided. Therefore, the display device 10 shown in FIG. 14 can also be called a display module.
A display device without an FPC or the like can also be called a display panel.

The terminal portion 15 is electrically connected to the FPC 242 via the connection layer 243 .

FIG. 14 shows a configuration in which the terminal section 15 has a layered structure of the wiring 16b and a conductive layer made of the same conductive film as the pixel electrode 225. In FIG. Thus, by configuring the terminal portion 15 by stacking a plurality of conductive layers, it is possible not only to reduce the electrical resistance but also to increase the mechanical strength, which is preferable.

For the insulating layers 211 and 221, a material into which impurities such as water and hydrogen are difficult to diffuse is preferably used. That is, the insulating layers 211 and 221 can function as barrier films. With such a structure, even if a moisture-permeable material is used for the first substrate 201 and the second substrate 202, external impurities can be prevented from entering the light-emitting element 254, the transistor, and the like. It is possible to effectively suppress it, and a highly reliable display device can be realized.

FIG. 14 shows the case of having a hollow sealing structure having a space 250 between the first substrate 201 and the second substrate 202 . For example, space 250 may be filled with an inert gas such as nitrogen or a noble gas. Further, the space 250 may be filled with a liquid crystal material or a fluid material such as oil. Alternatively, space 250 may be evacuated. Note that the sealing method is not limited to this, and solid sealing filled with resin or the like may be used.

[Cross-sectional configuration example 2]
FIG. 15 shows a configuration example of a display device suitable for use with the pixel portion 11 and the signal line driver circuit 13 bent.

The display device 10 shown in FIG. 15 has a solid sealing structure in which a first substrate 201 and a second substrate 202 are bonded together by a sealing material 260 .

An adhesive layer 261 is provided over the first substrate 201 , an insulating layer 216 is provided over the adhesive layer 261 , and a transistor, a light-emitting element, and the like are provided over the insulating layer 216 . Insulating layer 216 is insulating layer 2
As with 21, a material in which impurities such as water and hydrogen are difficult to diffuse can be used.

Also, an adhesive layer 262 is provided between the second substrate 202 and the insulating layer 221 .

Further, as shown in FIG. 15, the insulating layer 213 has openings on the outer peripheral side of the first substrate 201 with respect to the pixel portion 11 and the signal line driving circuit 13 . For example, when a resin material is used as the insulating layer 213, it is preferable to provide an opening surrounding the pixel portion 11, the signal line driver circuit 13, and the like. With such a configuration, the vicinity of the side surface of the insulating layer 213 in contact with the outside,
Since the portions overlapping with the pixel portion 11, the signal line driver circuit 13, and the like are not continuous, diffusion of impurities such as water and hydrogen from the outside through the insulating layer 213 can be suppressed.

By forming a solid sealing structure as shown in FIG. 15, the first substrate 201 and the second substrate 202
It becomes easier to keep the distance between the Therefore, the first substrate 201 and the second substrate 2
As 02, a substrate having flexibility can be preferably used. Therefore, the pixel portion 11
, the scanning line driving circuit 12, and the signal line driving circuit 13 can be partially or entirely bent for use. For example, by attaching the display device 10 to a curved surface or folding the pixel portion of the display device 10, various types of electronic devices can be realized.
[Modification]
An example of a touch panel having a touch sensor will be described below.

FIG. 16 illustrates an example of a touch panel in which an on-cell touch sensor is applied to the configuration illustrated in FIG. 14 .

A conductive layer 291 and a conductive layer 292 are provided on the outer surface of the second substrate 202, and an insulating layer 294 is provided to cover them. A conductive layer 293 is provided over the insulating layer 294 . The conductive layer 293 is electrically connected to two conductive layers 292 provided with the conductive layer 291 interposed therebetween through an opening provided in the insulating layer 294 . An insulating layer 294 and a substrate 296 are bonded together by an adhesive layer 295 .

A capacitance formed between the conductive layer 291 and the conductive layer 292 changes as the object to be sensed approaches. This makes it possible to detect the approach or contact of the object to be detected. By arranging the plurality of conductive layers 291 and the plurality of conductive layers 292 in a grid pattern, position information can be obtained.

A terminal portion 299 is provided in a region near the outer periphery of the second substrate 202 . Terminal part 2
99 is electrically connected to the FPC 297 via the connection layer 298 .

Here, the substrate 296 can also be used as a substrate that is directly touched by a sensing object such as a finger or a stylus. In that case, it is preferable to provide a protective layer (ceramic coat, etc.) on the substrate 296 . The protective layer is, for example, silicon oxide, aluminum oxide, yttrium oxide,
Inorganic insulating materials such as yttria stabilized zirconia (YSZ) can be used. Alternatively, tempered glass may be used for the substrate 296 . The tempered glass can be used after being physically or chemically treated by an ion exchange method, an air-cooling tempering method, or the like, and applying compressive stress to its surface. By providing the touch sensor on one surface of the tempered glass and providing the opposite surface on, for example, the outermost surface of the electronic device and using it as a touch surface, the thickness of the entire device can be reduced.

As the touch sensor, for example, a capacitive touch sensor can be applied. The capacitance method includes a surface capacitance method, a projected capacitance method, and the like. Projected capacitance methods include a self-capacitance method, a mutual capacitance method, and the like. It is preferable to use the mutual capacitance method because it enables simultaneous multi-point detection. A case where a projected capacitive touch sensor is applied will be described below.

It should be noted that the present invention is not limited to this, and various sensors capable of detecting the approach or contact of an object to be detected such as a finger or a stylus can also be applied.

Here, the configuration of a so-called on-cell touch panel in which wirings and the like forming a touch sensor are formed on the outer surface of the second substrate 202 is shown, but the configuration is not limited to this. For example, a configuration of an external (out-cell) touch panel or an in-cell touch panel may be applied. By using an on-cell or in-cell touch panel structure, the thickness of the display panel can be reduced even if the touch panel function is added to the display panel.

The above is the description of the cross-sectional configuration example.

[About each component]
Below, each component shown above is demonstrated.

〔substrate〕
A material having a flat surface can be used for a substrate included in the display device. A material that transmits the light is used for the substrate on the side from which the light from the light-emitting element is extracted. For example, materials such as glass, quartz, ceramic, sapphire, and organic resin can be used.

By using a thin substrate, the weight and thickness of the display device can be reduced. Furthermore, a flexible display device can be realized by using a substrate that is thick enough to be flexible.

Examples of glass that can be used include non-alkali glass, barium borosilicate glass, and aluminoborosilicate glass.

Materials having flexibility and transparency to visible light include, for example, glass having a thickness sufficient to have flexibility, polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), and polyacrylonitrile resins. , polyimide resin, polymethylmethacrylate resin, polycarbonate (PC) resin, polyethersulfone (PE
S) resins, polyamide resins, cycloolefin resins, polystyrene resins, polyamideimide resins, polyvinyl chloride resins, polytetrafluoroethylene (PTFE) resins, and the like. In particular, it is preferable to use a material with a low coefficient of thermal expansion, and for example, polyamideimide resin, polyimide resin, PET, etc. can be preferably used. A substrate obtained by impregnating glass fibers with an organic resin, or a substrate obtained by mixing an inorganic filler with an organic resin to reduce the coefficient of thermal expansion can also be used. Since a substrate using such a material is light in weight, a display device using the substrate can also be light in weight.

In addition, since the substrate on the side from which emitted light is not extracted does not need to have a light-transmitting property, a metal substrate or the like can be used in addition to the above substrates. Since the metal substrate has high thermal conductivity and can easily conduct heat to the entire sealing substrate, local temperature rise in the display device can be suppressed, which is preferable.

The material constituting the metal substrate is not particularly limited, but metals such as aluminum, copper, and nickel, or alloys such as aluminum alloys and stainless steel can be preferably used.

Alternatively, a substrate subjected to insulation treatment by oxidizing the surface of the metal substrate, forming an insulating film on the surface, or the like may be used. For example, an insulating film may be formed using a coating method such as a spin coating method or a dipping method, an electrodeposition method, a vapor deposition method, or a sputtering method. For example, an oxide film may be formed on the surface of the substrate.

A flexible substrate is provided with a hard coat layer (such as a silicon nitride layer) that protects the surface of the display device from scratches, etc., and a layer made of a material that can disperse pressure (such as an aramid resin layer).
etc. may be laminated. In addition, an insulating film with low water permeability may be laminated on a flexible substrate in order to suppress deterioration in life of the light-emitting element due to moisture or the like. For example, an inorganic insulating material such as silicon nitride, silicon oxynitride, aluminum oxide, or aluminum nitride can be used.

The substrate can also be used by laminating a plurality of layers. In particular, when a structure including a glass layer is employed, barrier properties against water and oxygen can be improved, and a highly reliable display device can be obtained.
For example, a substrate in which a glass layer, an adhesive layer, and an organic resin layer are stacked in this order from the side closer to the light emitting element can be used. By providing such an organic resin layer, breakage and cracking of the glass layer can be suppressed, and the mechanical strength can be improved. By applying such a composite material of a glass material and an organic resin to a substrate, a highly reliable and flexible display device can be obtained.

[transistor]
A transistor included in a display device includes a conductive layer functioning as a gate electrode, a conductive layer functioning as a back gate electrode, a semiconductor layer, a conductive layer functioning as a source electrode, a conductive layer functioning as a drain electrode, and a gate insulator. and an insulating layer functioning as a layer.

In other words, the transistor included in the display device of one embodiment of the present invention has a structure in which gate electrodes are provided above and below a channel.

The crystallinity of the semiconductor material used for the transistor is not particularly limited, and amorphous semiconductors,
Any of crystalline semiconductors (a microcrystalline semiconductor, a polycrystalline semiconductor, a single crystal semiconductor, or a semiconductor partially including a crystal region) may be used. It is preferable to use a crystalline semiconductor because deterioration of transistor characteristics can be suppressed.

As a semiconductor material used for a transistor, for example, an oxide semiconductor can be used for a semiconductor layer. In particular, it is preferable to use an oxide semiconductor having a wider bandgap than silicon. A semiconductor material with a wider bandgap and a lower carrier density than silicon is preferably used because the current in the off state of the transistor can be reduced.

For example, at least indium (In) or zinc (Zn
) is preferably included. More preferably, In-M-Zn oxide (M is Al, Ti,
metals such as Ga, Ge, Y, Zr, Sn, La, Ce or Hf).

In particular, the semiconductor layer has a plurality of crystal parts, the c-axes of the crystal parts are oriented substantially perpendicular to the formation surface of the semiconductor layer or the upper surface of the semiconductor layer, and grains are provided between adjacent crystal parts. It is preferable to use an oxide semiconductor layer in which no field is observed.

Since such an oxide semiconductor does not have a crystal grain boundary, cracks in the oxide semiconductor layer due to stress when the display panel is bent are suppressed. therefore,
Such an oxide semiconductor can be suitably used for a display device or the like that is flexible and used in a curved manner.

By using an oxide semiconductor having such crystallinity for a semiconductor layer, variation in electrical characteristics is suppressed, and a highly reliable transistor can be realized.

In addition, a transistor using an oxide semiconductor having a bandgap larger than that of silicon is
The low off-state current allows charge accumulated in the capacitor connected in series with the transistor to be held for a long time. By applying such a transistor to a pixel,
It is also possible to stop the driving circuit while maintaining the gradation of the image displayed in each display area.
As a result, a display device with extremely low power consumption can be realized. Alternatively, it is possible to operate by switching between a drive mode operating at a normal frame frequency and a drive mode operating at a low frame frequency. In a drive mode that operates at a low frame frequency, the power consumption required for writing image data is reduced by extending the interval between writing image data once and then writing the next image data. be able to.

[Conductive layer]
In addition to the gate, source and drain of transistors, materials that can be used for conductive layers such as various wirings and electrodes constituting display devices include aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, A metal such as tantalum or tungsten, or an alloy containing this as a main component can be used. Also, a film containing these materials can be used as a single layer or as a laminated structure. For example, a single-layer structure of an aluminum film containing silicon, a two-layer structure in which an aluminum film is stacked over a titanium film, a two-layer structure in which an aluminum film is stacked over a tungsten film, and a copper film over a copper-magnesium-aluminum alloy film. A two-layer structure, a two-layer structure in which a copper film is laminated on a titanium film, a two-layer structure in which a copper film is laminated on a tungsten film, a titanium film or a titanium nitride film, and an aluminum film or a copper film overlaid thereon and further a titanium film or a titanium nitride film is formed thereon, a molybdenum film or a molybdenum nitride film is laminated thereon, an aluminum film or a copper film is laminated thereon, and a molybdenum film or a There is a three-layer structure that forms a molybdenum nitride film, and the like. Note that an oxide such as indium oxide, tin oxide, or zinc oxide may be used. Further, it is preferable to use copper containing manganese because the controllability of the shape by etching is increased.

In addition, light-transmitting materials that can be used for conductive layers such as various wirings and electrodes that constitute a display device include indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, and gallium-added oxide. Conductive oxides such as zinc or graphene can be used. Alternatively, metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, or titanium, or alloy materials containing such metal materials can be used. Alternatively, a nitride of the metal material (eg, titanium nitride) or the like may be used. Note that when a metal material or an alloy material (or a nitride thereof) is used, it may be thin enough to have translucency. Alternatively, a stacked film of any of the above materials can be used as the conductive layer. For example, it is preferable to use a laminated film of a silver-magnesium alloy and indium tin oxide, because the conductivity can be increased.

[Insulating layer]
Examples of insulating materials that can be used for each insulating layer, overcoat, spacer, etc. include resins such as acrylic and epoxy resins, resins having siloxane bonds such as silicone resins, silicon oxide, silicon oxynitride, and silicon nitride oxide. , silicon nitride, and aluminum oxide can also be used.

Further, the light-emitting element is preferably provided between a pair of insulating films with low water permeability. As a result, it is possible to prevent impurities such as water from entering the light-emitting element, and to prevent deterioration of the reliability of the device.

Examples of the insulating film with low water permeability include a film containing nitrogen and silicon such as a silicon nitride film and a silicon nitride oxide film, a film containing nitrogen and aluminum such as an aluminum nitride film, and the like. again,
A silicon oxide film, a silicon oxynitride film, an aluminum oxide film, or the like may be used.

For example, the water vapor permeation amount of an insulating film with low water permeability is 1×10 ⁻⁵ [g/(m ² ·day)
] or less, preferably 1×10 ⁻⁶ [g/(m ² day)] or less, more preferably 1×1
0 ⁻⁷ [g/(m ² ·day)] or less, more preferably 1×10 ⁻⁸ [g/(m ² ·d
ay)] below.

[Adhesive layer, sealing material]
As the adhesive layer and the sealing material, various curable adhesives such as photocurable adhesives such as ultraviolet curable adhesives, reaction curable adhesives, thermosetting adhesives, and anaerobic adhesives can be used. These adhesives include epoxy resin, acrylic resin, silicone resin, phenol resin, polyimide resin, imide resin, PVC (polyvinyl chloride) resin, PVB (polyvinyl butyral).
resin, EVA (ethylene vinyl acetate) resin, and the like. In particular, a material with low moisture permeability such as epoxy resin is preferable. Also, a two-liquid mixed type resin may be used. Alternatively, an adhesive sheet or the like may be used.

Moreover, the resin may contain a desiccant. For example, a substance that adsorbs moisture by chemisorption, such as oxides of alkaline earth metals (calcium oxide, barium oxide, etc.) can be used. Alternatively, a substance that adsorbs moisture by physical adsorption, such as zeolite or silica gel, may be used. If a desiccant is contained, it is possible to prevent impurities such as moisture from entering the functional element, which is preferable because the reliability of the display panel is improved.

Further, by mixing a filler having a high refractive index or a light scattering member with the above resin, the light extraction efficiency from the light emitting element can be improved. For example, titanium oxide, barium oxide,
Zeolite, zirconium, etc. can be used.

[Light emitting element]
As the light-emitting element, an element capable of emitting light by itself can be used, and an element whose luminance is controlled by current or voltage is included in its category. For example, a light-emitting diode (LED), an organic EL element, an inorganic EL element, or the like can be used.

The light emitting element may be of top emission type, bottom emission type, or dual emission type. A conductive film that transmits visible light is used for the electrode on the light extraction side. A conductive film that reflects visible light is preferably used for the electrode on the side from which light is not extracted.

The EL layer has at least a light-emitting layer. The EL layer is a layer other than the light-emitting layer, which includes a substance with a high hole-injection property, a substance with a high hole-transport property, a hole-blocking material, a substance with a high electron-transport property, a substance with a high electron-injection property, or a bipolar material. A layer containing a substance (a substance having a high electron-transport property and a high hole-transport property) or the like may be further included.

Either a low-molecular-weight compound or a high-molecular-weight compound can be used in the EL layer, and an inorganic compound may be included. Each layer constituting the EL layer is formed by a vapor deposition method (including a vacuum vapor deposition method).
, a transfer method, a printing method, an inkjet method, a coating method, or the like.

When a voltage higher than the threshold voltage of the light-emitting element is applied between the cathode and the anode, holes are injected into the EL layer from the anode side and electrons are injected from the cathode side. The injected electrons and holes recombine in the EL layer, and the light-emitting substance contained in the EL layer emits light.

When a light-emitting element emitting white light is used as the light-emitting element, the EL layer preferably contains two or more kinds of light-emitting substances. For example, white light emission can be obtained by selecting light-emitting substances such that the light emitted from each of two or more light-emitting substances has a complementary color relationship. for example,
Luminous substances that emit light such as R (red), G (green), B (blue), Y (yellow), O (orange), etc.
or among luminescent substances that emit light containing spectral components of two or more colors selected from among R, G, and B,
It preferably contains two or more. In addition, it is preferable to use a light-emitting element having two or more peaks in the spectrum of light emission from the light-emitting element within the range of wavelengths in the visible light region (for example, 350 nm to 750 nm). Moreover, the emission spectrum of the material having a peak in the yellow wavelength region is preferably a material having spectral components in the green and red wavelength regions as well.

The EL layer preferably has a structure in which a light-emitting layer containing a light-emitting material that emits light of one color and a light-emitting layer containing a light-emitting material that emits light of another color are stacked. For example, a plurality of light-emitting layers in the EL layer may be laminated in contact with each other, or may be laminated via a region that does not contain any light-emitting material. For example, a configuration in which a region is provided between a fluorescent-emitting layer and a phosphorescent-emitting layer and contains the same material as the fluorescent-emitting layer or the phosphorescent-emitting layer (e.g., host material, assist material) and does not contain any of the emitting materials. good too. This facilitates fabrication of the light-emitting element and reduces the driving voltage.

Further, the light emitting element may be a single element having one EL layer, or may be a tandem element in which a plurality of EL layers are laminated via a charge generation layer.

Conductive films that transmit visible light include, for example, indium oxide and indium tin oxide (ITO:
Indium Tin Oxide), indium zinc oxide, zinc oxide, gallium-added zinc oxide, or the like can be used. In addition, metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, or titanium, alloys containing these metal materials, or nitrides of these metal materials (for example, Titanium nitride) or the like can also be used by forming it thin enough to have translucency. again,
A laminated film of any of the above materials can be used as the conductive layer. For example, it is preferable to use a laminated film of a silver-magnesium alloy and ITO because the conductivity can be increased. Alternatively, graphene or the like may be used.

For the conductive film that reflects visible light, metal materials such as aluminum, gold, platinum, silver, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, or palladium, or alloys containing these metal materials are used. can be done. Moreover, lanthanum, neodymium, germanium, or the like may be added to the metal material or alloy. In addition, alloys containing aluminum (aluminum alloys) such as aluminum-titanium alloys, aluminum-nickel alloys, aluminum-neodymium alloys, silver-copper alloys, silver-palladium-copper alloys,
Alloys containing silver, such as alloys of silver and magnesium, can be used. Alloys containing silver and copper are
It is preferable because of its high heat resistance. Further, by stacking a metal film or an oxide semiconductor film in contact with the aluminum alloy film, oxidation of the aluminum alloy film can be suppressed. the metal film;
Materials for the oxide semiconductor film include titanium, titanium oxide, and the like. Alternatively, a conductive film that transmits visible light and a film made of a metal material may be stacked. For example, a laminated film of silver and ITO, a laminated film of an alloy of silver and magnesium and ITO, or the like can be used.

Each of the conductive layers may be formed using an evaporation method or a sputtering method. others,
It can be formed using an ejection method such as an inkjet method, a printing method such as a screen printing method, or a plating method.

In addition, the layer containing the above-described light-emitting layer, a substance with high hole-injection property, a substance with high hole-transport property, a substance with high electron-transport property, a substance with high electron-injection property, a bipolar substance, etc. Each may have an inorganic compound such as a quantum dot, or a polymer compound (oligomer, dendrimer, polymer, etc.). For example, by using quantum dots in the light-emitting layer, it can function as a light-emitting material.

The quantum dot materials include colloidal quantum dot materials, alloy quantum dot materials,
A core-shell quantum dot material, a core quantum dot material, or the like can be used. Also, materials containing element groups of groups 12 and 16, 13 and 15, or 14 and 16 may be used. or cadmium, selenium, zinc, sulfur, phosphorus, indium, tellurium,
Quantum dot materials containing elements such as lead, gallium, arsenic, and aluminum may also be used.

[Colored layer]
Materials that can be used for the colored layer include metal materials, resin materials, and resin materials containing pigments or dyes.

[Light shielding layer]
Materials that can be used for the light shielding layer include carbon black, oxide semiconductors, composite oxides containing a solid solution of a plurality of oxide semiconductors, and the like. Alternatively, a laminated film of films containing a material for the colored layer can be used as the light shielding layer. For example, a layered structure of a film containing a material used for a colored layer transmitting light of a certain color and a film containing a material used for a colored layer transmitting light of another color can be used. By using a common material for the colored layer and the light shielding layer, it is possible to use a common apparatus and to simplify the process, which is preferable.

[Connection layer]
An anisotropic conductive film (ACF: Anis
otropic Conductive Film) and anisotropic conductive paste (ACP:
Anisotropic Conductive Paste) and the like can be used.

The above is the description of each component.

This embodiment can be implemented by appropriately combining at least part of it with other embodiments described herein.

(Embodiment 3)
In this embodiment, an example of a method for manufacturing a display device using a flexible substrate is described.

Here, a layer including a display element, a circuit, a wiring, an electrode, an insulating layer, an optical member such as a colored layer and a light shielding layer, and the like is collectively referred to as an element layer. For example, the element layer includes a light-emitting element, and in addition to the light-emitting element, wirings electrically connected to the light-emitting element and elements such as transistors used for pixels and circuits may be provided.

Further, here, a flexible member that supports an element layer when a light-emitting element is completed (a manufacturing process is completed) is referred to as a substrate. For example, the substrate includes an extremely thin film having a thickness of 10 nm or more and 300 μm or less.

As a method for forming an element layer over a flexible substrate having an insulating surface, there are typically the following two methods. One is a method of forming an element layer directly on a flexible substrate. The other method is to form an element layer on a support substrate different from the flexible substrate, separate the element layer from the support substrate, and transfer the element layer to the substrate. Although not described in detail here, in addition to the above two methods, a method of forming an element layer on an inflexible substrate and thinning the substrate by polishing or the like to impart flexibility. There is also

When the material forming the substrate has heat resistance against the heat applied in the process of forming the element layer, it is preferable to form the element layer directly on the substrate because the process is simplified. At this time, it is preferable to form the element layer in a state where the substrate is fixed to the supporting base material, because it facilitates transportation within and between apparatuses.

In the case of using a method of forming an element layer on a supporting base material and then transferring it to a substrate, first, a release layer and an insulating layer are laminated on the supporting base material, and the element layer is formed on the insulating layer. Subsequently, separation is performed between the supporting substrate and the element layer, and the element layer is transferred to the substrate. At this time, a material that causes peeling at the interface between the support substrate and the release layer, at the interface between the release layer and the insulating layer, or within the release layer may be selected.
In this method, by using a material with high heat resistance for the support base material and the peeling layer, the upper limit of the temperature applied when forming the element layer can be increased, resulting in higher reliability. This is preferable because an element layer having elements can be formed.

For example, as the separation layer, a layer containing a high-melting-point metal material such as tungsten and a layer containing an oxide of the metal material are stacked to be used. As the insulating layer over the separation layer, a layer in which a plurality of layers of silicon oxide, silicon nitride, silicon oxynitride, silicon nitride oxide, or the like is stacked is preferably used. In this specification, oxynitride refers to a material that contains more oxygen than nitrogen in its composition, and nitride oxide refers to a material that contains more nitrogen than oxygen in its composition. Point.

Examples of methods for separating the element layer and the support substrate include applying a mechanical force, etching the separation layer, and permeating the separation interface with a liquid. Alternatively, separation may be performed by heating or cooling by utilizing the difference in thermal expansion between the two layers forming the separation interface.

When starting the peeling, it is preferable to first form the starting point of the peeling and allow the peeling to progress from the starting point. The starting point of peeling is formed by locally heating a part of the insulating layer or peeling layer with a laser beam or the like, or by physically cutting or penetrating a part of the insulating layer or peeling layer with a sharp member. be able to.

Further, if the separation is possible at the interface between the support substrate and the insulating layer, the separation layer may not be provided.

For example, by using glass as the support base material and using an organic resin such as polyimide as the insulating layer, the separation can be performed at the interface between the glass and the organic resin. Also, the remaining organic resin such as polyimide can be used as the substrate.

Alternatively, a heat-generating layer may be provided between the support base material and the insulating layer made of an organic resin, and the heat-generating layer may be heated so that the separation may be performed at the interface between the heat-generating layer and the insulating layer. Various materials can be used for the heat-generating layer, such as a material that generates heat by applying current, a material that generates heat by absorbing light, and a material that generates heat by applying a magnetic field. For example, the heat generating layer can be selected from semiconductors, metals, and insulators.

An example of a more specific manufacturing method is described below. In the manufacturing method described below, a flexible input/output device of one embodiment of the present invention can be manufactured by changing the layer formed as the layer to be peeled.

First, an island-shaped separation layer 303 is formed on a production substrate 301 , and a layer 3 to be separated is formed on the separation layer 303 .
05 is formed (FIG. 17(A)). Separately from this, an island-shaped separation layer 323 is formed over a formation substrate 321, and a layer 325 to be separated is formed over the separation layer 323 (FIG. 17B).

Although an example of forming an island-shaped release layer is shown here, the present invention is not limited to this. In this step, a material is selected so that when the layer to be separated is separated from the formation substrate, separation occurs at the interface between the formation substrate and the separation layer, the interface between the separation layer and the layer to be separated, or in the separation layer. In this embodiment mode, the case where separation occurs at the interface between the layer to be peeled and the peeling layer is exemplified, but the present invention is not limited to this depending on the combination of the materials used for the peeling layer and the layer to be peeled. When the layer to be peeled has a laminated structure, the layer in contact with the peeling layer is particularly referred to as the first layer.

For example, when the separation layer has a stacked structure of a tungsten film and a tungsten oxide film, separation occurs at the interface (or in the vicinity of the interface) between the tungsten film and the tungsten oxide film, and part of the separation layer is formed on the side of the layer to be separated. (Tungsten oxide film here) may remain. Further, the peeling layer remaining on the side of the layer to be peeled may be removed later.

For example, when the separation layer has a stacked structure of a tungsten film and a tungsten oxide film, separation occurs at the interface (or in the vicinity of the interface) between the tungsten film and the tungsten oxide film, and part of the separation layer is formed on the side of the layer to be separated. (Tungsten oxide film here) may remain. Further, the peeling layer remaining on the side of the layer to be peeled may be removed later.

As a manufacturing substrate, a substrate having heat resistance that can withstand at least the processing temperature during the manufacturing process is used. As a manufacturing substrate, for example, a glass substrate, a quartz substrate, a sapphire substrate, a semiconductor substrate, a ceramic substrate, a metal substrate, a resin substrate, a plastic substrate, or the like can be used.

When a glass substrate is used as a production substrate, an insulating film such as a silicon oxide film, a silicon oxynitride film, a silicon nitride film, or a silicon nitride oxide film is formed as a base film between the production substrate and the separation layer. It is preferable because it can prevent contamination from

The release layer is an element selected from tungsten, molybdenum, titanium, tantalum, niobium, nickel, cobalt, zirconium, zinc, ruthenium, rhodium, palladium, osmium, iridium, and silicon, an alloy material containing the element, or the element. It can be formed using a compound material or the like containing. The crystal structure of the layer containing silicon may be amorphous, microcrystalline, or polycrystalline. Alternatively, an oxide semiconductor such as aluminum oxide, gallium oxide, zinc oxide, titanium dioxide, indium oxide, indium tin oxide, indium zinc oxide, or In—Ga—Zn oxide may be used. It is preferable to use a refractory metal material such as tungsten, titanium, or molybdenum for the separation layer because the degree of freedom in the process of forming the layer to be separated increases.

The release layer can be formed by, for example, a sputtering method, a plasma CVD method, a coating method (including a spin coating method, a droplet discharge method, a dispensing method, etc.), a printing method, or the like. The thickness of the release layer is, for example, 10 nm or more and 200 nm or less, preferably 20 nm or more and 100 nm or less.

When the separation layer has a single-layer structure, it is preferable to form a tungsten layer, a molybdenum layer, or a layer containing a mixture of tungsten and molybdenum. Alternatively, a layer containing an oxide or oxynitride of tungsten, a layer containing an oxide or oxynitride of molybdenum, or a layer containing an oxide or oxynitride of a mixture of tungsten and molybdenum may be formed. note that,
A mixture of tungsten and molybdenum corresponds, for example, to an alloy of tungsten and molybdenum.

In the case where a layer containing tungsten and a layer containing oxide of tungsten are formed as the separation layer, the layer containing tungsten is formed and an insulating film formed using oxide is formed thereover. , the fact that a layer containing a tungsten oxide is formed at the interface between the tungsten layer and the insulating film may be utilized. In addition, the surface of the layer containing tungsten is subjected to thermal oxidation treatment, oxygen plasma treatment, nitrous oxide (N ₂ O) plasma treatment, treatment with a strong oxidizing solution such as ozone water, or the like to remove tungsten oxide. You may form a layer containing. Plasma treatment and heat treatment may be performed in an atmosphere of oxygen, nitrogen, nitrous oxide alone, or in a mixed gas atmosphere of these gases and other gases. By changing the surface state of the peeling layer by the above plasma treatment or heat treatment, it is possible to control the adhesion between the peeling layer and an insulating film to be formed later.

Note that the separation layer may not be provided when separation can be performed at the interface between the formation substrate and the layer to be separated. For example, glass is used as a production substrate, and an organic resin such as polyimide, polyester, polyolefin, polyamide, polycarbonate, or acrylic is formed in contact with the glass. Next, laser irradiation or heat treatment is performed to improve adhesion between the manufacturing substrate and the organic resin. Then, an insulating film, a transistor, and the like are formed on the organic resin. After that, laser irradiation is performed at a higher energy density than the previous laser irradiation or heat treatment is performed at a higher temperature than the previous heat treatment, whereby separation can be performed at the interface between the formation substrate and the organic resin. Also, when stripping
Separation may be performed by infiltrating a liquid into the interface between the production substrate and the organic resin.

In this method, since an insulating film, a transistor, and the like are formed over an organic resin having low heat resistance, high temperature cannot be applied to the substrate in the manufacturing process. Here, since a high-temperature manufacturing process is not essential for a transistor using an oxide semiconductor, the transistor can be preferably formed over an organic resin.

The organic resin may be used as a substrate constituting the device, or the organic resin may be removed and another substrate may be attached to the exposed surface of the layer to be peeled using an adhesive. Further, another substrate (support film) may be attached to the organic resin using an adhesive.

Alternatively, a metal layer may be provided between the formation substrate and the organic resin, and the metal layer may be heated by passing an electric current through the metal layer, so that the separation may be performed at the interface between the metal layer and the organic resin.

The insulating layer (first layer) formed in contact with the separation layer is preferably formed to have a single layer or multiple layers using a silicon nitride film, a silicon oxynitride film, a silicon oxide film, a silicon nitride oxide film, or the like. . Note that the material is not limited to this, and an optimum material can be selected according to the material used for the release layer.

The insulating layer can be formed using a sputtering method, a plasma CVD method, a coating method, a printing method, or the like.
C. or lower, a dense film with extremely high moisture resistance can be obtained. note that,
The thickness of the insulating layer is preferably 10 nm or more and 3000 nm or less, more preferably 200 nm or more and 1500 nm or less.

Next, the production substrate 301 and the production substrate 321 are attached to each other using the adhesive layer 307 so that the surfaces on which the layers to be separated are formed face each other, and the adhesive layer 307 is cured (see FIG. 17 (
C)).

Note that the formation substrate 301 and the formation substrate 321 are preferably attached to each other under a reduced pressure atmosphere.

Although FIG. 17C shows the case where the peeling layers 303 and 323 have different sizes, peeling layers having the same size may be used as shown in FIG. 17D.

The adhesive layer 307 is arranged so as to overlap with the peeling layer 303 , the layer to be peeled 305 , the layer to be peeled 325 , and the peeling layer 323 . Then, the end of the adhesive layer 307 is the release layer 303 or the release layer 323 .
It is preferably located inside the end of at least one of (the one to be peeled off first). Accordingly, the formation substrate 301 and the formation substrate 321 can be prevented from being in close contact with each other, and a decrease in yield in the subsequent separation step can be suppressed.

For the adhesive layer 307, for example, various curable adhesives such as a photocurable adhesive such as an ultraviolet curable adhesive, a reaction curable adhesive, a thermosetting adhesive, and an anaerobic adhesive can be used. These adhesives include epoxy resins, acrylic resins, silicone resins, phenol resins, polyimide resins, imide resins, PVC resins, PVB resins, EVA resins, and the like. In particular, a material with low moisture permeability such as epoxy resin is preferable. As the adhesive, it is preferable to use a material with low fluidity to the extent that it can be placed only in a desired area. For example, adhesive sheets, adhesive sheets, sheet-like or film-like adhesives may be used. For example, OCA (optical
l clear adhesive) film can be preferably used.

The adhesive may have adhesiveness before bonding, or may develop adhesiveness by heating or light irradiation after bonding.

Moreover, the resin may contain a desiccant. For example, a substance that adsorbs moisture by chemisorption, such as oxides of alkaline earth metals (calcium oxide, barium oxide, etc.) can be used. Alternatively, a substance that adsorbs moisture by physical adsorption, such as zeolite or silica gel, may be used. If a desiccant is contained, deterioration of the functional element due to penetration of moisture in the air can be suppressed, and the reliability of the device is improved, which is preferable.

Next, a peeling starting point is formed by laser light irradiation (FIGS. 18A and 18B).

Either of the formation substrate 301 and the formation substrate 321 may be separated. When the peeling layers have different sizes, they may be peeled from a substrate having a large peeling layer formed thereon, or from a substrate having a small peeling layer formed thereon. When an element such as a semiconductor element or a light-emitting element is manufactured only on one substrate, it may be separated from the substrate on which the element is formed or from the other substrate.
Here, an example in which the formation substrate 301 is peeled first is shown.

A region where the adhesive layer 307 in a cured state, the layer to be peeled 305, and the peeling layer 303 overlap is irradiated with laser light (see arrow P1 in FIG. 18A).

By removing part of the first layer, the starting point of peeling can be formed (see the region surrounded by the dotted line in FIG. 18B). At this time, not only the first layer but also other layers of the layer to be peeled 305 and the peeling layer 3
03, a portion of the adhesive layer 307 may be removed.

Laser light is preferably applied from the side of the substrate provided with the peeling layer to be peeled off. When a region where the separation layer 303 and the separation layer 323 overlap is irradiated with laser light, cracks are formed only in the layer 305 to be separated from the layers 305 and 325 to be separated, so that the production substrate 301 and the formation substrate 301 are selectively separated. The peeling layer 303 can be peeled off (see the region enclosed by the dotted line in FIG. 18B. Here, an example of removing part of each layer forming the layer 305 to be peeled off is shown).

Then, the layer to be separated 305 and the production substrate 301 are separated from the starting point of separation (FIGS. 18C and 18D). As a result, the layer to be peeled 305 is separated from the manufacturing substrate 301 to the manufacturing substrate 321 .
can be transposed to

For example, the layer 305 to be peeled and the formation substrate 301 may be separated from the starting point of separation by physical force (separation by a human hand or a jig, separation while rotating a roller, or the like).

In addition, liquid such as water is permeated into the interface between the peeling layer 303 and the layer to be peeled 305 to form the production substrate 3 .
01 and the layer to be peeled 305 may be separated. Liquid permeates between the separation layer 303 and the layer to be separated 305 due to capillary action, so that the layers can be easily separated. In addition, it is possible to prevent the static electricity generated at the time of peeling from adversely affecting the functional elements included in the layer 305 to be peeled (such as static electricity destroying the semiconductor elements).

Next, the exposed layer 305 to be peeled and the substrate 331 are bonded together using an adhesive layer 333,
The adhesive layer 333 is cured (FIG. 19(A)).

Note that the layer 305 to be peeled and the substrate 331 are preferably attached to each other under a reduced pressure atmosphere.

Next, a peeling starting point is formed by laser light irradiation (FIGS. 19B and 19C).

A region where the adhesive layer 333 in a cured state, the layer to be peeled 325, and the peeling layer 323 overlap is irradiated with the laser light (see arrow P2 in FIG. 19B). By removing part of the first layer, the starting point of separation can be formed (see the region surrounded by the dotted line in FIG. 19C. Here, an example of removing part of each layer constituting the layer 325 to be separated) ). At this time, not only the first layer,
Other layers of the layer to be peeled 325 and part of the peeling layer 323 and the adhesive layer 333 may be removed.

Laser light is preferably emitted from the formation substrate 321 side provided with the separation layer 323 .

Then, the layer to be separated 325 and the production substrate 321 are separated from the starting point of separation (FIG. 19D). Accordingly, the layers 305 and 325 to be separated can be transferred to the substrate 331 .

After that, another substrate can be attached to the layer 325 to be peeled.

The exposed layer 325 to be peeled and the substrate 341 are bonded together by the adhesive layer 343, and the adhesive layer 3
43 is cured (FIG. 20(A)). Here, an example in which the substrate 341 is provided with openings in advance is shown.

As described above, the layer to be peeled can be sandwiched between the pair of flexible substrates.

After that, as shown in FIG. 20B, unnecessary end portions of the substrates 331, 341, etc. may be cut off and removed. At this time, part of the ends of the layer to be peeled 305 and the layer to be peeled 325 may be cut at the same time.

A flexible device can be manufactured by the above method. By using the structure described in the above embodiment mode for the layer to be separated, a flexible display device can be manufactured.

In the above-described method for manufacturing a light-emitting device of one embodiment of the present invention, after a pair of manufacturing substrates provided with a separation layer and a layer to be separated are attached to each other, starting points of separation are formed by irradiation with laser light, The separation is performed after making the separation layer and the layer to be separated easy to separate. Thereby, the yield of the peeling process can be improved.

Further, after bonding in advance a pair of production substrates each having a layer to be peeled formed thereon,
After peeling, the substrate constituting the device to be manufactured can be attached to the layer to be peeled. Therefore, when the layers to be peeled are attached to each other, production substrates with low flexibility can be attached to each other, and the alignment accuracy of attachment can be improved more than when flexible substrates are attached to each other. can be done.

Note that, as shown in FIG. 21A, the end of the peeled region 351 of the layer 305 to be peeled is
It is preferably located inside the edge of the release layer 303 . Thereby, the yield of the peeling process can be increased. Further, when there are a plurality of regions 351, a peeling layer 303 may be provided for each region 351 as shown in FIG.
A plurality of regions 351 may be provided on one release layer 303 .

The above is the description of the method for manufacturing a flexible display device.

This embodiment can be implemented by appropriately combining at least part of it with other embodiments described herein.

(Embodiment 4)
In this embodiment, examples of electronic devices to which the display device of one embodiment of the present invention can be applied will be described.

An electronic device or a lighting device can be manufactured using the display device of one embodiment of the present invention. By using the display device of one embodiment of the present invention, an electronic device or a lighting device in which a large capacity can be obtained even with a small area can be manufactured. By using the display device of one embodiment of the present invention, an electronic device or a lighting device in which a large capacity can be obtained even when grayscale display is performed while holding a low voltage can be manufactured.

Examples of electronic devices include televisions, desktop or notebook personal computers, computer monitors, digital cameras, digital video cameras, digital photo frames, mobile phones, mobile game machines, personal digital assistants, audio Examples include playback devices and large game machines such as pachinko machines.

An electronic device or a lighting device of one embodiment of the present invention includes an inner wall or an outer wall of a house or building,
Alternatively, it can be incorporated along the curved surface of the interior or exterior of an automobile.

An electronic device of one embodiment of the present invention may include a secondary battery, and it is preferable that the secondary battery can be charged using contactless power transmission.

Secondary batteries include, for example, lithium ion secondary batteries such as lithium polymer batteries (lithium ion polymer batteries) using a gel electrolyte, nickel-metal hydride batteries, nickel-cadmium batteries, organic radical batteries, lead-acid batteries, air secondary batteries, nickel zinc batteries, silver-zinc batteries, and the like.

An electronic device of one embodiment of the present invention may have an antenna. An image, information, or the like can be displayed on the display portion by receiving a signal with the antenna. Moreover, when an electronic device has an antenna and a secondary battery, the antenna may be used for contactless power transmission.

The electronic device of one embodiment of the present invention includes sensors (force, displacement, position, speed, acceleration, angular velocity, number of rotations, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor or infrared).

An electronic device of one embodiment of the present invention can have various functions. For example, functions to display various information (still images, moving images, text images, etc.) on the display, touch panel functions, functions to display calendars, dates or times, functions to execute various software (programs), wireless communication function, a function of reading a program or data recorded on a recording medium, and the like.

Furthermore, in an electronic device having a plurality of display units, one display unit mainly displays image information and another display unit mainly displays character information, or a plurality of display units has a function of displaying parallax. By displaying an image, it can have a function of displaying a stereoscopic image. In addition, in electronic devices with an image receiving unit, the function of shooting still images or moving images, the function of automatically or manually correcting the captured image, the function of saving the captured image to a recording medium (external or built into the electronic device) , a function of displaying a captured image on a display portion, and the like. Note that the electronic device of one embodiment of the present invention is not limited to these functions, and can have various functions.

An example of an electronic device having a curved display portion 7000 is shown in FIGS. The display portion 7000 has a curved display surface, and can perform display along the curved display surface. Note that the display portion 7000 may have flexibility.

The display portion 7000 is manufactured using the display device or the like of one embodiment of the present invention. According to one embodiment of the present invention, an electronic device with reduced power consumption, a curved display portion, and high reliability can be provided.

22A and 22B show an example of a mobile phone. Mobile phone 71 shown in FIG.
00 and a mobile phone 7110 shown in FIG.
000, operation button 7103, external connection port 7104, speaker 7105, microphone 71
06 and so on. A mobile phone 7110 shown in FIG. 22B further has a camera 7107 .

Each mobile phone has a touch sensor on the display unit 7000 . Any operation such as making a call or inputting characters can be performed by touching the display portion 7000 with a finger, a stylus, or the like.

In addition, by operating the operation button 7103, the power can be turned on or off, or the display unit 7000 can be turned on or off.
You can switch the type of image displayed in the . For example, it is possible to switch from the mail creation screen to the main menu screen.

Also, by providing a detection device such as a gyro sensor or an acceleration sensor inside the mobile phone, it is possible to determine the orientation of the mobile phone (vertical or horizontal) and automatically switch the screen display orientation of the display unit 7000. can be Further, switching of the orientation of the screen display can be performed by touching the display portion 7000, operating the operation button 7103, voice input using the microphone 7106, or the like.

22C and 22D show an example of a portable information terminal. A mobile information terminal 7200 in FIG. 22C and a mobile information terminal 7210 in FIG. 22D each include a housing 7201 and a display portion 7000 . Further, it may have operation buttons, an external connection port, a speaker, a microphone, an antenna, a camera, a battery, or the like. The display portion 7000 includes a touch sensor. The portable information terminal can be operated by touching the display portion 7000 with a finger, a stylus, or the like.

The mobile information terminal exemplified in the present embodiment has one or more functions selected from, for example, a telephone, a notebook, an information browsing device, and the like. Specifically, each can be used as a smartphone. The personal digital assistants exemplified in the present embodiment can execute various applications such as mobile phones, e-mails, reading and creating texts, playing music, Internet communication, and computer games.

The mobile information terminal 7200 and the mobile information terminal 7210 can display characters, image information, and the like on multiple surfaces. For example, as shown in FIGS. 22C and 22D, three operation buttons 7202 can be displayed on one side, and information 7203 indicated by rectangles can be displayed on the other side. FIG. 22(C) shows an example in which information is displayed on the upper side of the portable information terminal, and FIG.
Now, an example in which information is displayed on the side of the portable information terminal will be shown. Information may also be displayed on three or more surfaces of the mobile information terminal.

Examples of information include SNS (social networking service) notifications, displays that notify incoming e-mails and phone calls, titles or sender names of e-mails, date and time, remaining battery power, antenna reception strength, etc. Alternatively, an operation button, an icon, or the like may be displayed at the position where the information is displayed instead of the information.

For example, the user of the mobile information terminal 7200 wears the mobile information terminal 7200 in the breast pocket of his clothes.
is housed, its display (here, information 7203) can be confirmed.

Specifically, the phone number or name of the caller of the incoming call is transmitted to the mobile information terminal 7200.
be displayed in a position where it can be observed from above. The user can check the display and determine whether or not to receive the call without taking out the portable information terminal 7200 from the pocket.

FIG. 22E shows an example of a television device. The television device 7300 includes a housing 7
A display unit 7000 is incorporated in 301 . Here, the housing 7 is supported by a stand 7303.
301 is shown.

The television set 7300 shown in FIG. 22E can be operated using operation switches provided in the housing 7301 or a separate remote controller 7311 . Alternatively, the display unit 70
00 may be provided with a touch sensor, and the display unit 7000 may be operated by touching the display unit 7000 with a finger or the like. The remote controller 7311 may have a display section for displaying information output from the remote controller 7311 . A channel and a volume can be operated with operation keys or a touch panel provided in the remote controller 7311, and images displayed on the display portion 7000 can be operated.

Note that the television device 7300 is configured to include a receiver, a modem, and the like. The receiver can receive general television broadcasts. Also, by connecting to a wired or wireless communication network via a modem, one-way (from the sender to the receiver) or two-way (between the sender and the receiver, or between the receivers, etc.) information communication is performed. is also possible.

FIG. 22F shows an example of a lighting device having a curved light emitting portion.

A light-emitting portion included in the lighting device illustrated in FIG. 22F is manufactured using the display device or the like of one embodiment of the present invention. According to one embodiment of the present invention, a lighting device with reduced power consumption, a curved light-emitting portion, and high reliability can be provided.

A light emitting portion 7411 included in a lighting device 7400 illustrated in FIG. 22F has a structure in which two convexly curved light emitting portions are symmetrically arranged. Therefore, it is possible to illuminate all directions centering on the illumination device 7400 .

Further, the light-emitting portion included in the lighting device 7400 may have flexibility. The light-emitting portion may be fixed by a plastic member or a movable frame or other member, and the light-emitting surface of the light-emitting portion may be freely curved according to the application.

The lighting device 7400 has a base portion 7401 having an operation switch 7403 and a light emitting portion supported by the base portion 7401 .

Although the lighting device in which the light-emitting portion is supported by the base portion is illustrated here, the housing including the light-emitting portion may be fixed to the ceiling or suspended from the ceiling.
Since the light-emitting surface can be curved, the light-emitting surface can be curved concavely to brightly illuminate a specific area, or the light-emitting surface can be curved convexly to brightly illuminate an entire room.

FIG. 23(A) to FIG. 23(I) show a flexible and bendable display portion 70.
01 shows an example of a personal digital assistant.

The display portion 7001 is manufactured using the display device or the like of one embodiment of the present invention. For example, a display device or the like that can be bent with a curvature radius of 0.01 mm or more and 150 mm or less can be applied. Further, the display portion 7001 may include a touch sensor, and the portable information terminal can be operated by touching the display portion 7001 with a finger or the like. According to one embodiment of the present invention, a highly reliable electronic device including a flexible display portion can be provided.

23A and 23B are perspective views showing an example of a portable information terminal. Personal digital assistant 75
00 includes a housing 7501, a display portion 7001, a drawer member 7502, operation buttons 7503, and the like.

A portable information terminal 7500 includes a flexible display portion 7001 rolled in a housing 7501 . The display portion 7001 can be pulled out using the drawer member 7502 .

Further, the portable information terminal 7500 can receive a video signal by a built-in control portion, and can display the received video on the display portion 7001 . In addition, the portable information terminal 7500 incorporates a battery. Alternatively, the housing 7501 may be provided with a terminal portion for connecting a connector, and a video signal and power may be directly supplied from the outside through a wire.

In addition, an operation button 7503 can be used to turn on/off the power, switch images to be displayed, and the like. Note that although FIGS. 23A and 23B show an example in which the operation buttons 7503 are arranged on the side surface of the mobile information terminal 7500, the mobile information terminal 7500 is not limited to this.
may be arranged on the same surface (front surface) as the display surface of , or on the back surface.

FIG. 23B shows a portable information terminal 7500 with the display portion 7001 pulled out.
An image can be displayed on the display portion 7001 in this state. 23A in which part of the display portion 7001 is rolled up and the state in FIG. good too. For example, Figure 23
By hiding the rolled portion of the display portion 7001 in the state of (A), power consumption of the portable information terminal 7500 can be reduced.

Note that a reinforcing frame may be provided on the side of the display portion 7001 so that the display surface of the display portion 7001 is flat when the display portion 7001 is pulled out.

In addition to this configuration, a configuration in which a speaker is provided in the housing and an audio signal received together with a video signal is used to output audio may be employed.

FIGS. 23C to 23E show an example of a foldable portable information terminal.
FIG. 23(C) shows the unfolded state, FIG. 23(D) shows the state in the middle of changing from one of the unfolded state and the folded state to the other, and FIG. 23(E) shows the portable information terminal in the folded state. 7600 is shown. The portable information terminal 7600 is excellent in portability in the folded state, and excellent in viewability due to a wide seamless display area in the unfolded state.

The display portion 7001 is supported by three housings 7601 connected by hinges 7602 . By bending between the two housings 7601 via the hinge 7602, the portable information terminal 7600 can be reversibly transformed from the unfolded state to the folded state.

23F and 23G show an example of a foldable portable information terminal. Fig. 23(F)
23G shows a portable information terminal 7650 in which the display portion 7001 is folded on the inside and the display portion 7001 is folded on the outside. A portable information terminal 7650 has a display portion 7001 and a non-display portion 7651 . When the portable information terminal 7650 is not used, the display portion 7001 can be folded so that the display portion 7001 faces inside.
Stain and damage can be suppressed.

FIG. 23H shows an example of a flexible portable information terminal. A mobile information terminal 7700 includes a housing 7701 and a display portion 7001 . Furthermore, a button 7703a as input means
, 7703b, speakers 7704a and 7704b as audio output means, external connection port 7
705, a microphone 7706, and the like. In addition, the mobile information terminal 7700 can include a flexible battery 7709 . The battery 7709 is used for the display unit 7, for example.
001 may be overlapped.

The housing 7701, the display portion 7001, and the battery 7709 are flexible. for that reason,
It is easy to bend the portable information terminal 7700 into a desired shape and to twist the portable information terminal 7700 . For example, the portable information terminal 7700 can be used with the display portion 7001 facing inside or outside. Or portable information terminal 7700
can also be used in a rolled state. Thus, the housing 7701 and the display unit 7
001 can be freely deformed, the portable information terminal 7700 has the advantage of being less likely to be damaged even if it is dropped or unintended external force is applied.

In addition, since the portable information terminal 7700 is lightweight, the housing 7701 can be used in a variety of situations, such as by holding the upper portion of the housing 7701 with a clip or the like and hanging it, or by fixing the housing 7701 to a wall surface with a magnet or the like. can be conveniently used in

FIG. 23I shows an example of a wristwatch-type portable information terminal. A portable information terminal 7800 includes a band 7801, a display portion 7001, an input/output terminal 7802, operation buttons 7803, and the like. Band 7801 functions as a housing. In addition, the mobile information terminal 7800 can include a flexible battery 7805 . The battery 7805 is used for the display unit 70, for example.
01 or band 7801 or the like.

The band 7801, the display portion 7001, and the battery 7805 are flexible. Therefore, it is easy to bend the portable information terminal 7800 into a desired shape.

The operation button 7803 can have various functions such as time setting, power on/off operation, wireless communication on/off operation, manner mode execution/cancellation, and power saving mode execution/cancellation. . For example, an operating system incorporated in the mobile information terminal 7800 can freely set the functions of the operation buttons 7803 .

An application can be activated by touching an icon 7804 displayed on the display portion 7001 with a finger or the like.

In addition, the mobile information terminal 7800 can perform short-range wireless communication conforming to communication standards. For example, by intercommunicating with a headset capable of wireless communication, hands-free communication is also possible.

In addition, the portable information terminal 7800 may have an input/output terminal 7802 . Input/output terminal 7
802, data can be exchanged directly with other information terminals via connectors. Also, charging can be performed through the input/output terminal 7802 . Note that the charging operation of the portable information terminal illustrated in this embodiment may be performed by contactless power transmission without using the input/output terminal.

FIG. 24(A) shows the appearance of an automobile 7900. As shown in FIG. FIG. 24B shows the driver's seat of automobile 7900 . An automobile 7900 has a vehicle body 7901, wheels 7902, a windshield 7903, lights 7904, fog lamps 7905, and the like.

The display device of one embodiment of the present invention can be used for the display portion of the automobile 7900 or the like. For example, the display device of one embodiment of the present invention can be provided in the display portions 7910 to 7917 illustrated in FIG.

Display portions 7910 and 7911 are provided on the windshield of the automobile. In one embodiment of the present invention, an electrode included in the display device is formed using a light-transmitting conductive material, so that the display device can be a so-called see-through display device, in which the opposite side can be seen through. A display device in a see-through state does not obstruct the view even when the automobile 7900 is driven. Therefore, the display device of one embodiment of the present invention can be installed on the windshield of the automobile 7900 . Note that when a transistor or the like is provided in the display device, a light-transmitting transistor such as an organic transistor using an organic semiconductor material or a transistor using an oxide semiconductor is preferably used.

A display portion 7912 is provided in a pillar portion. A display unit 7913 is provided on the dashboard portion. For example, by displaying an image from an imaging unit provided on the vehicle body on the display portion 7912, the field of view blocked by the pillar can be complemented. Similarly, the display unit 7
In 913, the view obstructed by the dashboard can be complemented, and in the display part 7914, the view obstructed by the door can be complemented. That is, by projecting an image from the imaging means provided outside the automobile, blind spots can be compensated for and safety can be enhanced.
In addition, by projecting an image that supplements the invisible part, safety confirmation can be performed more naturally and without discomfort.

Also, the display unit 7917 is provided on the handle. Display portion 7915, display portion 791
6, or display 7917 can provide navigation information, speedometer, tachometer, mileage, fuel level, gear status, air conditioning settings, and a variety of other information. In addition, the display items and layout displayed on the display unit can be appropriately changed according to the user's preference. Note that the above information can also be displayed on the display portions 7910 to 7914 .

Note that the display portions 7910 to 7917 can also be used as lighting devices.

A display portion to which the display device of one embodiment of the present invention is applied may be flat. In this case, the display device of one embodiment of the present invention may have a curved surface and no flexibility.

24C and 24D show an example of a digital signage (electronic signboard). Digital signage includes a housing 8000, a display portion 8001, speakers 8003, and the like. Furthermore, it can have an LED lamp, an operation key (including a power switch or an operation switch), connection terminals, various sensors, a microphone, and the like.

FIG. 24(D) is a digital signage attached to a cylindrical post.

As the display portion 8001 is wider, the amount of information that can be provided at one time can be increased. In addition, the wider the display portion 8001, the more conspicuous it is, and the more effective the advertisement can be, for example.

By applying a touch panel to the display portion 8001, not only an image or a moving image can be displayed on the display portion 8001 but also the user can intuitively operate the display portion 8001, which is preferable. Further, when used for providing information such as route information or traffic information, usability can be enhanced by intuitive operation.

A portable game machine illustrated in FIG. 24E includes a housing 8101, a housing 8102, and a display portion 8103.
, a display portion 8104, a microphone 8105, a speaker 8106, operation keys 8107, a stylus 8108, and the like.

The portable game machine shown in FIG. 24E has two display units (display unit 8103 and display unit 810).
4). Note that the number of display portions included in the electronic device of one embodiment of the present invention is not limited to two, and may be one or three or more. In the case where an electronic device has a plurality of display portions, at least one display portion may include the display device of one embodiment of the present invention.

FIG. 24F illustrates a notebook personal computer including a housing 8111 and a display portion 811.
2. It has a keyboard 8113, a pointing device 8114, and the like.

The display device of one embodiment of the present invention can be applied to the display portion 8112 .

FIG. 25A shows the appearance of camera 8400 with viewfinder 8500 attached.

A camera 8400 includes a housing 8401, a display portion 8402, operation buttons 8403, a shutter button 8404, and the like. A detachable lens 8406 is attached to the camera 8400 .

Here, the camera 8400 has a structure in which the lens 8406 can be removed from the housing 8401 and replaced, but the lens 8406 and the housing may be integrated.

Camera 8400 can take an image by pressing shutter button 8404 . Further, the display portion 8402 has a function as a touch panel, and an image can be captured by touching the display portion 8402 .

A housing 8401 of the camera 8400 has a mount with electrodes and a viewfinder 850
0, a strobe device or the like can be connected.

A viewfinder 8500 includes a housing 8501, a display portion 8502, buttons 8503, and the like.

The housing 8501 has mounts that engage the mounts of the camera 8400 so that the viewfinder 8500 can be attached to the camera 8400 . Further, the mount has an electrode, and an image or the like received from the camera 8400 through the electrode can be displayed on the display portion 8502 .

A button 8503 has a function as a power button. The display on the display portion 8502 can be turned on/off by a button 8503 .

The display device of one embodiment of the present invention can be applied to the display portion 8402 of the camera 8400 and the display portion 8502 of the viewfinder 8500 .

Note that in FIG. 25A, the camera 8400 and the viewfinder 8500 are separate electronic devices and configured to be detachable. A viewfinder may be built in.

FIG. 25B shows the appearance of the head mounted display 8200. As shown in FIG.

The head mounted display 8200 includes a mounting portion 8201, a lens 8202, a main body 82
03, a display unit 8204, a cable 8205, and the like. A battery 8206 is built in the mounting portion 8201 .

Cable 8205 supplies power from battery 8206 to body 8203 . body 82
03 includes a wireless receiver or the like, and can display video information such as received image data on the display portion 8204 . In addition, by capturing the movement of the user's eyeballs and eyelids with a camera provided in the main body 8203 and calculating the coordinates of the user's viewpoint based on the information, the user's viewpoint can be used as an input means. can.

Also, the mounting portion 8201 may be provided with a plurality of electrodes at positions where the user touches. The main body 8203 detects the current flowing through the electrodes in accordance with the movement of the user's eyeball,
It may have a function of recognizing the viewpoint of the user. It may also have a function of monitoring the user's pulse by detecting the current flowing through the electrode. Moreover, the mounting portion 820
1 may have various sensors such as a temperature sensor, a pressure sensor, an acceleration sensor, etc., and may have a function of displaying the biological information of the user on the display unit 8204 . Alternatively, the movement of the user's head may be detected and the image displayed on the display portion 8204 may be changed according to the movement.

The display device of one embodiment of the present invention can be applied to the display portion 8204 .

25(C) and (D) show the appearance of the head mounted display 8300. FIG.

A head-mounted display 8300 has a housing 8301 , two display portions 8302 , operation buttons 8303 , and band-shaped fixtures 8304 .

Head mounted display 8300 has two display units in addition to the functions of head mounted display 8200 .

Having two displays 8302 allows the user to see one display per eye. As a result, even when three-dimensional display using parallax is performed, a high-resolution image can be displayed. In addition, the display portion 8302 is curved in an arc with the eye of the user as the approximate center. As a result, the distance from the user's eyes to the display surface of the display unit is constant, so that the user can see more natural images. In addition, even if the brightness and chromaticity of the light from the display unit change depending on the viewing angle, since the user's eyes are positioned in the normal direction of the display surface of the display unit, Since the influence can be ignored, a more realistic image can be displayed.

An operation button 8303 has a function such as a power button. Further, a button other than the operation button 8303 may be provided.

Further, as shown in FIG. 25E, a lens 8305 may be provided between the display portion 8302 and the user's eyes. Since the lens 8305 allows the user to magnify the display portion 8302, the sense of presence is enhanced. At this time, as shown in FIG. 25(E), a dial 8306 for changing the position of the lens for diopter adjustment may be provided.

The display device of one embodiment of the present invention can be applied to the display portion 8302 . Since the display device of one embodiment of the present invention has extremely high definition, pixels are not visually recognized by the user even when the lens 8305 is used for magnification as shown in FIG. It can display high quality images.

FIGS. 26A to 26C show an example in which one display portion 8302 is provided. With such a configuration, the number of parts can be reduced.

The display unit 8302 can display two images, an image for the right eye and an image for the left eye, side by side in two regions on the left and right. Thereby, a stereoscopic image using binocular parallax can be displayed.

Alternatively, one image that can be viewed with both eyes may be displayed over the entire display portion 8302 . This makes it possible to display a panoramic image across both ends of the field of view.
heightened sense of reality.

Further, as shown in FIG. 26C, a lens 8305 may be provided. In the display unit 8302,
Two images may be displayed side by side, or one image may be displayed on the display portion 8302 and the same image may be viewed with both eyes through the lens 8305 .

This embodiment can be implemented by appropriately combining at least part of it with other embodiments described herein.

GL scanning line SL signal line V0 wiring ANODE current supply line M1 transistor M2 transistor M3 transistor M4 transistor M5 transistor MC capacitive element EL light emitting element CATHODE common wiring 100 transistor 102 substrate 104 insulating layer 106 conductive layer 108 oxide semiconductor layer 110 insulating layer 110t Film thickness 104t Film thickness 112 Metal oxide layer 116 Insulating layer 108i Channel region 108s Source region 108d Drain region 141a Opening 141b Opening 120a Conductive layer 120b Conductive layer PIX Pixel PIX_A Pixel PIX_B Pixel PIX_C Pixel PIX_D Pixel PIX_E Pixel PIX_F Pixel PIX_UL Pixel PIX_UR Pixel PIX_LL Pixel PIX_LR Pixel SUB Substrate 151 Conductive layer 152 Conductive layer 153 Conductive layer 154 Insulating layer 161 Oxide semiconductor layer 162 Oxide semiconductor layer 163 Insulating layer 171 Metal oxide layer 172 Metal oxide layer 173 Metal oxide layer 174 Insulating layer 181 Conductive layer 182 Conductive layer 183 Conductive layer 184 Conductive layer 185 Conductive layer 186 Insulating layer 187 Insulating layer 188 Insulating layer 190 Opening GL_LC Scanning line GL_EL Scanning line SL_LC Signal line SL_EL Signal line M6 Transistor LC Liquid crystal element 191 Layer 192 Electrode 193 Opening 10 Display Device 11 Pixel portion 12 Scanning line driving circuit 13 Signal line driving circuit 15 Terminal portion 16a Wiring 16b Wiring GL1 Scanning line GL2 Scanning line GL3 Scanning line V1 Wiring 201 Substrate 202 Substrate 211 Insulating layer 212 Insulating layer 213 Insulating layer 214 Insulating layer 215 Spacer 216 insulating layer 217 insulating layer 218 insulating layer 220 adhesive layer 221 insulating layer 222 EL layer 223 electrode 224 optical adjustment layer 225 pixel electrode 230a structure 230b structure 231 light shielding layer 232 colored layer 242 FPC
243 Connection layer 250 Space 251 Transistor 252 Transistor 253 Capacitive element 254 Light-emitting element 255 Transistor 260 Sealing material 261 Adhesive layer 262 Adhesive layer 271 Semiconductor layer 272 Conductive layer 273 Conductive layer 274 Conductive layer 275 Conductive layer 276 Insulating layer 291 Conductive layer 292 Conductive Layer 293 Conductive layer 294 Insulating layer 295 Adhesive layer 296 Substrate 297 FPC
298 connection layer 299 terminal portion 301 production substrate 303 separation layer 305 separation layer 307 adhesive layer 321 production substrate 323 separation layer 325 separation layer 331 substrate 333 adhesive layer 341 substrate 343 adhesive layer 351 region 7000 display portion 7001 display portion 7100 mobile phone 7101 housing 7103 operation button 7104 external connection port 7105 speaker 7106 microphone 7107 camera 7110 mobile phone 7200 portable information terminal 7201 housing 7202 operation button 7203 information 7210 portable information terminal 7300 television device 7301 housing 7303 stand 7311 remote controller 7400 lighting Device 7401 base portion 7403 operation switch 7411 light emitting portion 7500 portable information terminal 7501 housing 7502 member 7503 operation button 7600 portable information terminal 7601 housing 7602 hinge 7650 portable information terminal 7651 non-display portion 7700 portable information terminal 7701 housing 7703a button 7703b button 7704a Speaker 7704b Speaker 7705 External connection port 7706 Microphone 7709 Battery 7800 Portable information terminal 7801 Band 7802 Input/output terminal 7803 Operation button 7804 Icon 7805 Battery 7900 Automobile 7901 Car body 7902 Wheel 7903 Windshield 7904 Light 7905 Fog lamp 7910 Display 7911 Display 7912 Portion 7913 Display portion 7914 Display portion 7915 Display portion 7916 Display portion 7917 Display portion 8000 Housing 8001 Display portion 8003 Speaker 8101 Housing 8102 Housing 8103 Display portion 8104 Display portion 8105 Microphone 8106 Speaker 8107 Operation keys 8108 Stylus 8111 Housing 8112 Display Unit 8113 Keyboard 8114 Pointing device 8200 Head-mounted display 8201 Mounting unit 8202 Lens 8203 Main body 8204 Display unit 8205 Cable 8206 Battery 8300 Head-mounted display 8301 Housing 8302 Display unit 8303 Operation button 8304 Fixing tool 8305 Lens 8306 Dial 8400 Camera 8401 Housing 8402 Display unit 8403 Operation button 8404 Shutter button 8406 Lens 8500 Viewfinder 8501 Housing 8502 Display Part 8503 button

Claims (3)

a pixel having first to third transistors and a light-emitting element;
one of the source and the drain of the first transistor is electrically connected to a signal line and the other of the source and the drain is electrically connected to the gate electrode of the second transistor;
the second transistor has one of its source and drain electrically connected to a current supply line and the other of its source and drain electrically connected to a pixel electrode of the light emitting element;
one of the source and the drain of the third transistor is electrically connected to the wiring and the other of the source and the drain is electrically connected to the pixel electrode;
The first conductive layer functioning as a current supply line is arranged in the same layer as the second conductive layer functioning as a scanning line electrically connected to the gate electrode of the first transistor,
the third conductive layer functioning as the signal line is arranged in the same layer as the fourth conductive layer functioning as the wiring;
The third conductive layer and the fourth conductive layer extend in a direction intersecting the direction in which the first conductive layer and the second conductive layer extend, and the first conductive layer and arranged above the second conductive layer,
the first transistor has a gate electrode on a channel formation region;
the second conductive layer is arranged in a different layer than the gate electrode of the first transistor;
A fifth conductive layer electrically connected to the first conductive layer is arranged in the same layer as the third conductive layer and the fourth conductive layer, and is the source or the source of the second transistor. electrically connected to one of the drains,
the other of the source and the drain of the third transistor is electrically connected to a sixth conductive layer arranged in the same layer as the third conductive layer and the fourth conductive layer;
The semiconductor device, wherein the sixth conductive layer is electrically connected to the pixel electrode. a pixel having first to third transistors and a light-emitting element;
one of the source and the drain of the first transistor is electrically connected to a signal line and the other of the source and the drain is electrically connected to the gate electrode of the second transistor;
one of the source and the drain of the second transistor is electrically connected to a current supply line and the other of the source and the drain is electrically connected to the pixel electrode of the light emitting element;
one of the source and the drain of the third transistor is electrically connected to the wiring and the other of the source and the drain is electrically connected to the pixel electrode;
The first conductive layer functioning as a current supply line is arranged in the same layer as the second conductive layer functioning as a scanning line electrically connected to the gate electrode of the first transistor,
the third conductive layer functioning as the signal line is arranged in the same layer as the fourth conductive layer functioning as the wiring;
The third conductive layer and the fourth conductive layer extend in a direction intersecting the direction in which the first conductive layer and the second conductive layer extend, and the first conductive layer and arranged above the second conductive layer,
the first transistor has a gate electrode on a channel formation region;
the second conductive layer is arranged in a different layer than the gate electrode of the first transistor;
A fifth conductive layer electrically connected to the first conductive layer is arranged in the same layer as the third conductive layer and the fourth conductive layer, and is the source or the source of the second transistor. electrically connected to one of the drains,
the other of the source and the drain of the third transistor is electrically connected to a sixth conductive layer arranged in the same layer as the third conductive layer and the fourth conductive layer;
the sixth conductive layer is electrically connected to the pixel electrode through an opening of an insulating layer in contact with the sixth conductive layer;
The semiconductor device, wherein the opening overlaps with the first conductive layer. In claim 1 or claim 2,
The first to sixth conductive layers include a first film containing titanium or titanium nitride, a second film containing aluminum over the first film, and a and a third film containing titanium or titanium nitride.

Images