WO2022162486A1 - 表示装置 - Google Patents

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Publication number
WO2022162486A1
WO2022162486A1 PCT/IB2022/050284 IB2022050284W WO2022162486A1 WO 2022162486 A1 WO2022162486 A1 WO 2022162486A1 IB 2022050284 W IB2022050284 W IB 2022050284W WO 2022162486 A1 WO2022162486 A1 WO 2022162486A1
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WIPO (PCT)
Prior art keywords
layer
film
light
region
display device
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
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PCT/IB2022/050284
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English (en)
French (fr)
Japanese (ja)
Other versions
WO2022162486A8 (ja
Inventor
山崎舜平
池田隆之
岡崎健一
山根靖正
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Semiconductor Energy Laboratory Co Ltd
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Semiconductor Energy Laboratory Co Ltd
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Filing date
Publication date
Application filed by Semiconductor Energy Laboratory Co Ltd filed Critical Semiconductor Energy Laboratory Co Ltd
Priority to KR1020237025788A priority Critical patent/KR20230133866A/ko
Priority to JP2022577801A priority patent/JP7724805B2/ja
Priority to CN202280010483.6A priority patent/CN116803210A/zh
Priority to US18/273,122 priority patent/US20240090253A1/en
Publication of WO2022162486A1 publication Critical patent/WO2022162486A1/ja
Anticipated expiration legal-status Critical
Publication of WO2022162486A8 publication Critical patent/WO2022162486A8/ja
Priority to JP2025130825A priority patent/JP2025156533A/ja
Ceased legal-status Critical Current

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    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
    • H10K59/10—OLED displays
    • H10K59/17—Passive-matrix OLED displays
    • H10K59/173—Passive-matrix OLED displays comprising banks or shadow masks
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
    • H10K59/10—OLED displays
    • H10K59/12—Active-matrix OLED [AMOLED] displays
    • H10K59/121—Active-matrix OLED [AMOLED] displays characterised by the geometry or disposition of pixel elements
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
    • G09F9/00—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements
    • G09F9/30—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual elements
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
    • G09F9/00—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements
    • G09F9/30—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual elements
    • G09F9/33—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual elements being semiconductor devices, e.g. diodes
    • G09F9/335—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual elements being semiconductor devices, e.g. diodes being organic light emitting diodes [OLED]
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B33/00—Electroluminescent light sources
    • H05B33/02—Details
    • H05B33/06—Electrode terminals
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B33/00—Electroluminescent light sources
    • H05B33/12—Light sources with substantially two-dimensional [2D] radiating surfaces
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B33/00—Electroluminescent light sources
    • H05B33/12—Light sources with substantially two-dimensional [2D] radiating surfaces
    • H05B33/14—Light sources with substantially two-dimensional [2D] radiating surfaces characterised by the chemical or physical composition or the arrangement of the electroluminescent material, or by the simultaneous addition of the electroluminescent material in or onto the light source
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B33/00—Electroluminescent light sources
    • H05B33/12—Light sources with substantially two-dimensional [2D] radiating surfaces
    • H05B33/22—Light sources with substantially two-dimensional [2D] radiating surfaces characterised by the chemical or physical composition or the arrangement of auxiliary dielectric or reflective layers
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K50/00—Organic light-emitting devices
    • H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
    • H10K50/11—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers
    • H10K50/125—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers specially adapted for multicolour light emission, e.g. for emitting white light
    • H10K50/13—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers specially adapted for multicolour light emission, e.g. for emitting white light comprising stacked EL layers within one EL unit
    • H10K50/131—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers specially adapted for multicolour light emission, e.g. for emitting white light comprising stacked EL layers within one EL unit with spacer layers between the electroluminescent layers
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
    • H10K59/80—Constructional details
    • H10K59/805—Electrodes
    • H10K59/8051—Anodes
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
    • H10K59/80—Constructional details
    • H10K59/805—Electrodes
    • H10K59/8052—Cathodes
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K50/00—Organic light-emitting devices
    • H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
    • H10K50/11—OLEDs or polymer light-emitting diodes [PLED] characterised by the electroluminescent [EL] layers
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
    • H10K59/30—Devices specially adapted for multicolour light emission
    • H10K59/35—Devices specially adapted for multicolour light emission comprising red-green-blue [RGB] subpixels
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
    • H10K59/80—Constructional details
    • H10K59/88—Dummy elements, i.e. elements having non-functional features

Definitions

  • One embodiment of the present invention relates to a display device.
  • One embodiment of the present invention relates to a method for manufacturing a display device.
  • one aspect of the present invention is not limited to the above technical field.
  • Technical fields of one embodiment of the present invention disclosed in this specification and the like include semiconductor devices, display devices, light-emitting devices, power storage devices, memory devices, electronic devices, lighting devices, input devices, input/output devices, and driving methods thereof. , or methods for producing them, can be mentioned as an example.
  • a semiconductor device refers to all devices that can function by utilizing semiconductor characteristics.
  • Devices that require a high-definition display panel include, for example, smartphones, tablet terminals, and laptop personal computers.
  • stationary display devices such as television devices and monitor devices are also required to have higher definition along with higher resolution.
  • devices that require the highest definition include, for example, devices for virtual reality (VR) or augmented reality (AR).
  • VR virtual reality
  • AR augmented reality
  • Display devices that can be applied to display panels typically include liquid crystal display devices, organic EL (Electro Luminescence) elements, light-emitting devices equipped with light-emitting elements such as light-emitting diodes (LEDs), and electrophoretic display devices.
  • Examples include electronic paper that performs display by, for example.
  • the basic structure of an organic EL device is to sandwich a layer containing a light-emitting organic compound between a pair of electrodes. By applying a voltage to this device, light can be obtained from the light-emitting organic compound.
  • a display device to which such an organic EL element is applied does not require a backlight, which is required in a liquid crystal display device or the like.
  • Patent Document 1 describes an example of a display device using an organic EL element.
  • An object of one embodiment of the present invention is to provide a display device that can easily achieve high definition and a manufacturing method thereof.
  • An object of one embodiment of the present invention is to provide a display device having both high display quality and high definition.
  • An object of one embodiment of the present invention is to provide a high-contrast display device.
  • An object of one embodiment of the present invention is to provide a highly reliable display device.
  • An object of one embodiment of the present invention is to provide a display device having a novel structure or a method for manufacturing the display device.
  • An object of one embodiment of the present invention is to provide a method for manufacturing the above display device with high yield.
  • One aspect of the present invention aims to alleviate at least one of the problems of the prior art.
  • One embodiment of the present invention is a display device including a first light-emitting element and a second light-emitting element.
  • the first light emitting element has a first pixel electrode, a first EL layer, and a common electrode.
  • the second light emitting element has a second pixel electrode, a second EL layer, and a common electrode.
  • An insulating layer is provided between the first pixel electrode and the second pixel electrode.
  • the insulating layer has a first region that overlaps with the first EL layer, a second region that overlaps with the second EL layer, is positioned between the first region and the second region, and is located between the first EL layer and the second EL layer. and a third region that overlaps neither the layer nor the second EL layer.
  • a side surface of the first EL layer and a side surface of the second EL layer are located on the insulating layer and provided to face each other.
  • a common electrode is provided along the side surface of the first EL layer, the side surface of the second EL layer, and the top surface of the insulating layer.
  • the insulating layer includes an inorganic insulating material. The width of the insulating layer is two to four times the distance between the first pixel electrode and the second pixel electrode.
  • the present invention is a display device including a first light-emitting element and a second light-emitting element.
  • the first light emitting element has a first pixel electrode, a first EL layer, and a common electrode.
  • the second light emitting element has a second pixel electrode, a second EL layer, and a common electrode.
  • An insulating layer is provided between the first pixel electrode and the second pixel electrode.
  • the insulating layer has a first region that overlaps with the first EL layer, a second region that overlaps with the second EL layer, is positioned between the first region and the second region, and is located between the first EL layer and the second EL layer. and a third region that overlaps neither the layer nor the second EL layer.
  • a side surface of the first EL layer and a side surface of the second EL layer are located on the insulating layer and provided to face each other.
  • a common electrode is provided along the side surface of the first EL layer, the side surface of the second EL layer, and the top surface of the insulating layer.
  • the insulating layer includes an inorganic insulating material. The width of the insulating layer is two to four times the distance between the side surface of the first EL layer and the side surface of the second EL layer.
  • the width of the first region is greater than the width of the third region and is 300 nm or less
  • the width of the second region is greater than the width of the third region, Moreover, it is preferably 300 nm or less.
  • the sum of the width of the first region and the width of the second region is larger than twice the width of the third region. Furthermore, the sum of the width of the first region, the width of the second region, and the width of the third region is preferably 1000 nm or less.
  • the width of the third region is preferably 50 nm or more and 250 nm or less.
  • the display device preferably has an effective light emitting area ratio of 70% or more and less than 100%.
  • a display device with high definition and a manufacturing method thereof it is possible to provide a display device with high definition and a manufacturing method thereof.
  • a display device having both high display quality and high definition can be provided.
  • a display device with high contrast can be provided.
  • a highly reliable display device can be provided.
  • a display device having a novel structure or a method for manufacturing the display device can be provided.
  • at least one of the problems of the prior art can be alleviated.
  • 1A to 1D are diagrams showing configuration examples of a display device.
  • 2A and 2B are diagrams showing configuration examples of the display device.
  • 3A to 3F are diagrams illustrating an example of a method for manufacturing a display device.
  • 4A to 4F are diagrams illustrating an example of a method for manufacturing a display device.
  • 5A to 5C are diagrams illustrating an example of a method for manufacturing a display device.
  • 6A to 6D are diagrams showing configuration examples of the display device.
  • 7A to 7D are diagrams showing configuration examples of the display device.
  • 8A to 8E are diagrams illustrating an example of a method for manufacturing a display device.
  • 9A to 9C are diagrams showing configuration examples of the display device.
  • 10A to 10C are diagrams illustrating configuration examples of display devices.
  • 11A to 11C are diagrams illustrating configuration examples of display devices.
  • 12A and 12B are perspective views showing an example of a display module.
  • FIG. 13 is a cross-sectional view showing an example of a display device.
  • FIG. 14 is a cross-sectional view showing an example of a display device.
  • FIG. 15 is a cross-sectional view showing an example of a display device.
  • 16A to 16D are diagrams showing configuration examples of light-emitting elements.
  • 17A and 17B are diagrams illustrating configuration examples of a display device.
  • 18A and 18B are diagrams showing configuration examples of a display device.
  • 19A and 19B are diagrams illustrating examples of electronic devices.
  • 20A to 20D are diagrams illustrating examples of electronic devices.
  • 21A to 21F are diagrams illustrating examples of electronic devices.
  • 22A to 22F are diagrams illustrating examples of electronic devices.
  • 23A is an optical micrograph of a pixel according to Example 1.
  • FIG. 23B is a cross-sectional observation photograph of a pixel according to Example 1.
  • FIG. 24 is a cross-sectional observation photograph of a pixel according to Example 2.
  • FIG. 25A and 25B are display photographs of the display panel according to Example 2.
  • film and the term “layer” can be interchanged with each other.
  • conductive layer or “insulating layer” may be interchangeable with the terms “conductive film” or “insulating film.”
  • an EL layer refers to a layer provided between a pair of electrodes of a light-emitting element and containing at least a light-emitting substance (also referred to as a light-emitting layer) or a laminate including a light-emitting layer.
  • a display panel which is one aspect of a display device, has a function of displaying (outputting) an image or the like on a display surface. Therefore, the display panel is one aspect of the output device.
  • the substrate of the display panel is attached with a connector such as FPC (Flexible Printed Circuit) or TCP (Tape Carrier Package), or an IC is sometimes called a display panel module, a display module, or simply a display panel.
  • a connector such as FPC (Flexible Printed Circuit) or TCP (Tape Carrier Package)
  • an IC is sometimes called a display panel module, a display module, or simply a display panel.
  • One embodiment of the present invention is a display device including a light-emitting element (also referred to as a light-emitting device).
  • a display device has at least two light-emitting elements that emit light of different colors. Each light-emitting element has a pair of electrodes and an EL layer therebetween.
  • the light-emitting element is preferably an organic EL element (organic electroluminescence element). Two or more light-emitting elements with different emission colors have EL layers containing different materials.
  • a full-color display device can be realized by using three types of light-emitting elements that emit red (R), green (G), and blue (B) light.
  • the EL layer when part or all of the EL layer is separately formed between light emitting elements emitting different colors, it is known to form by vapor deposition using a shadow mask such as a metal mask.
  • a shadow mask such as a metal mask.
  • various influences such as the accuracy of the metal mask, misalignment between the metal mask and the substrate, bending of the metal mask, and broadening of the contour of the film to be formed due to vapor scattering, etc. cause island-like organic films. Since the shape and position of the film deviate from the design, it is difficult to increase the definition and aperture ratio of the display device. Therefore, measures have been taken to artificially increase the definition (also called pixel density) by applying a special pixel arrangement method such as a pentile arrangement.
  • an EL layer is processed into a fine pattern without using a shadow mask such as a metal mask.
  • a shadow mask such as a metal mask.
  • a first EL film and a first sacrificial film are laminated to cover two pixel electrodes.
  • a resist mask is formed on the first sacrificial film at a position overlapping with one pixel electrode (first pixel electrode).
  • a portion of the first sacrificial film and a portion of the first EL film that do not overlap with the resist mask are etched. At this time, the etching is finished when the other pixel electrode (second pixel electrode) is exposed.
  • a part of the first EL film also referred to as a first EL layer
  • a part of the sacrificial film (also referred to as a sacrificial layer) are formed thereon.
  • a sacrificial layer also referred to as a sacrificial layer
  • a second EL film and a second sacrificial film are laminated and formed.
  • a resist mask is formed at a position overlapping with the second pixel electrode.
  • a portion of the second sacrificial film that does not overlap the resist mask and a portion of the second EL film are etched in the same manner as described above.
  • the first EL layer and the first sacrificial layer are provided over the first pixel electrode, and the second EL layer and the second sacrificial layer are provided over the second pixel electrode. becomes. In this manner, the first EL layer and the second EL layer can be separately formed.
  • the first sacrificial layer and the second sacrificial layer are removed to expose the first EL layer and the second EL layer, and then a common electrode is formed to form a two-color light emitting element. can be separated.
  • EL layers of light emitting elements of three or more colors can be separately formed, and a display device having light emitting elements of three or four or more colors can be realized.
  • an electrode (also referred to as a first electrode, a connection electrode, or the like) is provided on the same surface as the pixel electrode, and the connection electrode and the common electrode are electrically connected.
  • the connection electrode is arranged outside the display portion where the pixel is provided.
  • it is preferable to provide a second sacrificial layer on the connection electrode. The first sacrificial layer and the second sacrificial layer provided over the connection electrode are etched simultaneously with the first sacrificial layer over the first EL layer and the second sacrificial layer over the second EL layer. can be removed.
  • the gap can be narrowed to 500 nm or less, 200 nm or less, 100 nm or less, or even 50 nm or less.
  • the aperture ratio can be brought close to 100%.
  • the aperture ratio can be 50% or more, 60% or more, 70% or more, 80% or more, or even 90% or more, and less than 100%.
  • the pattern of the EL layer itself can also be made much smaller than when a metal mask is used.
  • the thickness varies between the center and the edge of the pattern, so the effective area that can be used as the light emitting region is smaller than the area of the entire pattern. .
  • the pattern is formed by processing a film formed to have a uniform thickness, the thickness can be made uniform within the pattern, and even if the pattern is fine, almost the entire area of the pattern can emit light. It can be used as a region. Therefore, according to the above manufacturing method, both high definition and high aperture ratio can be achieved.
  • an insulating layer between two adjacent pixel electrodes.
  • the insulating layer is provided to cover the edge of the pixel electrode. A region on the pixel electrode covered with the insulating layer does not function as a light emitting region of the light emitting element. can increase
  • the end of the EL layer is located on the insulating layer.
  • the ends (side surfaces) of the two EL layers are arranged to face each other on the insulating layer. The narrower the distance between the two EL layers, the smaller the width of the insulating layer, so that the aperture ratio of the display device can be increased.
  • the width of the insulating layer provided between the two light emitting elements is larger than the distance between the two pixel electrodes, preferably 4 times or less, preferably 3.5 times or less, more preferably 3 times or less.
  • the width of the insulating layer is preferably 1.5 times or more, preferably 2 times or more, the distance between the two pixel electrodes.
  • the width of the insulating layer provided between the two light-emitting elements is greater than the distance between the two opposing side surfaces of the two EL layers, and is 4 times or less, preferably 3.5 times or less, more preferably 3 times. The following are preferable.
  • the width of the insulating layer is preferably 1.5 times or more, preferably 2 times or more, the distance between the two opposing sides of the two EL layers.
  • a display device in which fine light-emitting elements are integrated since a display device in which fine light-emitting elements are integrated can be realized, it is necessary to apply a special pixel arrangement method such as a pentile method to artificially increase the definition. Since there is no R, G, and B arranged in one direction, a so-called stripe arrangement, and a display device with a resolution of 500 ppi or more, 1000 ppi or more, or 2000 ppi or more, further 3000 ppi or more, and further 5000 ppi or more can be realized. Furthermore, it is possible to realize a display device with an effective light emitting area ratio (aperture ratio) of 50% or more, further 60% or more, further 70% or more and less than 100%.
  • an effective light emitting area ratio aperture ratio
  • the effective light emitting area ratio refers to the ratio of the area of a region that can be regarded as a light emitting region in one pixel to the area of one pixel calculated from the pixel repetition pitch of the display device.
  • FIG. 1A shows a schematic top view of a display device 100 of one embodiment of the present invention.
  • the display device 100 includes a plurality of light emitting elements 110R that emit red, a plurality of light emitting elements 110G that emit green, and a plurality of light emitting elements 110B that emit blue.
  • the light emitting region of each light emitting element is labeled with R, G, and B. As shown in FIG.
  • the light emitting elements 110R, 110G, and 110B are arranged in a matrix.
  • FIG. 1A shows a so-called stripe arrangement in which light emitting elements of the same color are arranged in one direction. Note that the arrangement method of the light emitting elements is not limited to this, and an arrangement method such as a delta arrangement or a zigzag arrangement may be applied, or a pentile arrangement may be used.
  • the light emitting elements 110R, 110G, and 110B are arranged in the X direction. In addition, light emitting elements of the same color are arranged in the Y direction intersecting with the X direction.
  • EL elements such as OLEDs (Organic Light Emitting Diodes) or QLEDs (Quantum-dot Light Emitting Diodes) are preferably used as the light emitting elements 110R, 110G, and 110B.
  • the light-emitting substance of the EL element include a substance that emits fluorescence (fluorescent material), a substance that emits phosphorescence (phosphorescence material), and a substance that exhibits thermally activated delayed fluorescence (thermally activated delayed fluorescence (TADF) material). ) and the like.
  • TADF thermally activated delayed fluorescence
  • a light-emitting substance included in an EL element not only an organic compound but also an inorganic compound (such as a quantum dot material) can be used.
  • FIG. 1B is a schematic cross-sectional view corresponding to dashed-dotted line A1-A2 in FIG. 1A
  • FIG. 1C is a schematic cross-sectional view corresponding to dashed-dotted line B1-B2.
  • FIG. 1B shows cross sections of the light emitting element 110R, the light emitting element 110G, and the light emitting element 110B.
  • the light emitting element 110R has a pixel electrode 111R, an EL layer 112R, an EL layer 114, and a common electrode 113.
  • the light emitting element 110G has a pixel electrode 111G, an EL layer 112G, an EL layer 114, and a common electrode 113.
  • the light-emitting element 110B has a pixel electrode 111B, an EL layer 112B, an EL layer 114, and a common electrode 113.
  • the EL layer 114 and the common electrode 113 are commonly provided for the light emitting elements 110R, 110G, and 110B.
  • the EL layer 114 can also be called a common layer.
  • the EL layer 112R of the light-emitting element 110R contains a light-emitting organic compound that emits light having an intensity in at least the red wavelength range.
  • the EL layer 112G included in the light-emitting element 110G contains a light-emitting organic compound that emits light having an intensity in at least the green wavelength range.
  • the EL layer 112B included in the light-emitting element 110B contains a light-emitting organic compound that emits light having an intensity in at least a blue wavelength range.
  • Each of the EL layer 112R, the EL layer 112G, and the EL layer 112B includes a layer containing a light-emitting organic compound (light-emitting layer), an electron injection layer, an electron transport layer, a hole injection layer, and a hole transport layer. You may have one or more of them.
  • the EL layer 114 can have a structure without a light-emitting layer.
  • the EL layer 114 has one or more of an electron injection layer, an electron transport layer, a hole injection layer, and a hole transport layer.
  • a pixel electrode 111R, a pixel electrode 111G, and a pixel electrode 111B are provided for each light emitting element. Further, the common electrode 113 and the EL layer 114 are provided as a continuous layer common to each light emitting element.
  • a conductive film having a property of transmitting visible light is used for one of the pixel electrodes and the common electrode 113, and a conductive film having a reflective property is used for the other.
  • An insulating layer 131 is provided to cover end portions of the pixel electrode 111R, the pixel electrode 111G, and the pixel electrode 111B.
  • the ends of the insulating layer 131 are preferably tapered. Note that the insulating layer 131 may be omitted if unnecessary.
  • the tapered end of the object means that the angle formed by the surface and the surface to be formed in the region of the end is greater than 0 degrees and less than 90 degrees, preferably 5 degrees or more. It refers to having a cross-sectional shape that is 70 degrees or less and that the thickness increases continuously from the end.
  • an inorganic insulating material for the insulating layer 131 it is preferable to use an inorganic insulating material for the insulating layer 131 .
  • Using an inorganic insulating material for the insulating layer 131 enables highly accurate microfabrication by photolithography, so the distance between adjacent pixels can be significantly reduced compared to the case of using an organic insulating material, and the aperture ratio can be increased. can be very high.
  • the insulating layer 131 preferably has tapered ends. Accordingly, step coverage of a film formed over the insulating layer 131, such as an EL layer provided to cover the end portion of the insulating layer 131, can be improved. Also, the insulating layer 131 is preferably thinner than the pixel electrode 111R and the like. By forming the insulating layer 131 to be thin, step coverage of a film formed over the insulating layer 131 can be improved.
  • An inorganic insulating material that can be used for the insulating layer 131 is an oxide or nitride film such as silicon oxide, silicon oxynitride, silicon nitride oxide, silicon nitride, aluminum oxide, aluminum oxynitride, or hafnium oxide. can be used. Alternatively, yttrium oxide, zirconium oxide, gallium oxide, tantalum oxide, magnesium oxide, lanthanum oxide, cerium oxide, neodymium oxide, or the like may be used.
  • the insulating layer 131 may be laminated with a film containing the inorganic insulating material.
  • Each of the EL layer 112R, the EL layer 112G, and the EL layer 112B has a region in contact with the upper surface of the pixel electrode and a region in contact with the surface of the insulating layer 131.
  • end portions of the EL layer 112R, the EL layer 112G, and the EL layer 112B are located over the insulating layer 131 .
  • a gap is provided between the two EL layers between the light emitting elements emitting different colors.
  • the EL layer 112R, the EL layer 112G, and the EL layer 112B are provided with a gap so as not to be in contact with each other.
  • the EL layers 112R are formed in strips so that the EL layers 112R are continuous in the Y direction.
  • the EL layer 112R and the like are formed in strips so that the EL layers 112R are continuous in the Y direction.
  • a space for dividing them is not required, and the area of the non-light-emitting region between the light-emitting elements can be reduced, so that the aperture ratio can be increased.
  • FIG. 1C shows the cross section of the light emitting element 110R as an example, but the light emitting elements 110G and 110B can also have the same shape.
  • a protective layer 121 is provided on the common electrode 113 to cover the light emitting elements 110R, 110G, and 110B.
  • the protective layer 121 has a function of preventing impurities such as water from diffusing into each light emitting element from above.
  • the protective layer 121 can have, for example, a single layer structure or a laminated structure including at least an inorganic insulating film.
  • inorganic insulating films include oxide films and nitride films such as silicon oxide films, silicon oxynitride films, silicon nitride oxide films, silicon nitride films, aluminum oxide films, aluminum oxynitride films, and hafnium oxide films.
  • a semiconductor material such as indium gallium oxide or indium gallium zinc oxide may be used for the protective layer 121 .
  • the protective layer 121 a laminated film of an inorganic insulating film and an organic insulating film can be used.
  • a structure in which an organic insulating film is sandwiched between a pair of inorganic insulating films is preferable.
  • the organic insulating film functions as a planarizing film. As a result, the upper surface of the organic insulating film can be flattened, so that the coverage of the inorganic insulating film thereon can be improved, and the barrier property can be enhanced.
  • the upper surface of the protective layer 121 is flat, when a structure (for example, a color filter, an electrode of a touch sensor, or a lens array) is provided above the protective layer 121, an uneven shape due to the structure below may be formed. This is preferable because it can reduce the impact.
  • a structure for example, a color filter, an electrode of a touch sensor, or a lens array
  • FIG. 1A also shows a connection electrode 111C electrically connected to the common electrode 113.
  • FIG. A potential to be supplied to the common electrode 113 (for example, an anode potential or a cathode potential) is applied to the connection electrode 111C.
  • the connection electrode 111C is provided outside the display area where the light emitting elements 110R and the like are arranged. Further, in FIG. 1A, the common electrode 113 is indicated by a dashed line.
  • connection electrodes 111C can be provided along the periphery of the display area. For example, it may be provided along one side of the periphery of the display area, or may be provided over two or more sides of the periphery of the display area. That is, when the top surface shape of the display area is rectangular, the top surface shape of the connection electrode 111C can be strip-shaped, L-shaped, U-shaped (square bracket-shaped), square, or the like.
  • FIG. 1D is a schematic cross-sectional view corresponding to the dashed-dotted line C1-C2 in FIG. 1A.
  • FIG. 1D shows a connection portion 130 where the connection electrode 111C and the common electrode 113 are electrically connected.
  • the common electrode 113 is provided on the connection electrode 111 ⁇ /b>C so as to be in contact therewith, and the protective layer 121 is provided to cover the common electrode 113 .
  • An insulating layer 131 is provided to cover the end of the connection electrode 111C.
  • FIG. 2A shows an enlarged view of the insulating layer 131 and its vicinity between two adjacent light emitting elements.
  • the light emitting element 110P and the light emitting element 110Q are shown as arbitrary two adjacent light emitting elements.
  • the light emitting elements 110P and 110Q are each independently one of the light emitting elements 110R, 110G, and 110B.
  • the light emitting element 110P has an EL layer 112P and a pixel electrode 111P
  • the light emitting element 110Q has an EL layer 112Q and a pixel electrode 111Q.
  • FIG. 2A shows the width W D of the insulating layer 131, the distance S G between the pixel electrode 111P and the pixel electrode 111Q, and the distance S E between the side surface of the EL layer 112P and the side surface of the EL layer 112Q.
  • the insulating layer 131 has a region that overlaps with the EL layer 112P, a region that overlaps with the EL layer 112Q, and a region that does not overlap with any of these.
  • the width of the region overlapping with the EL layer 112P is defined as width WP
  • the width of the region overlapping with the EL layer 112Q is defined as WQ. Note that the width of the region of the insulating layer 131 that does not overlap with any EL layer is the length obtained by subtracting the width WP and the width WQ from the width WD, and substantially matches the distance SE.
  • the width WD of the insulating layer 131 is made larger than the distance SG between the pair of pixel electrodes.
  • the width WD is 1.2 times or more, preferably 1.5 times or more, more preferably 2 times or more, and 8 times or less, preferably 6 times or less, more preferably 4 times the distance SG . It is preferable to make it 3 times or less, more preferably 3 times or less.
  • the width WD is preferably two to four times the distance SG .
  • the width WD is increased, misalignment between the pair of pixel electrodes and the insulating layer 131 can be tolerated, so that the manufacturing yield can be improved.
  • the smaller the width WD the more improved the definition, the aperture ratio, and the like. By setting the width WD within the above range, both high manufacturing yield and high definition or aperture ratio can be achieved.
  • the width W D of the insulating layer 131 is made larger than the distance S E between the side surface of the EL layer 112P and the side surface of the EL layer 112Q.
  • the width WD is 1.2 times or more, preferably 1.5 times or more, more preferably 2 times or more, and is 8 times or less, preferably 6 times or less, more preferably 4 times the distance SE . It is preferable to make it 3 times or less, more preferably 3 times or less.
  • the width WD is two to four times the distance SE .
  • the width WD is increased, misalignment between the end of each EL layer and the insulating layer 131 can be tolerated, so that the manufacturing yield can be improved.
  • the smaller the width WD the more improved the definition, the aperture ratio, and the like. By setting the width WD within the above range, both high manufacturing yield and high definition or aperture ratio can be achieved.
  • the insulating layer 131 has a width W P of a region overlapping with the EL layer 112P larger than a width of a region overlapping neither the EL layer 112P nor the EL layer 112Q (that is, the distance S E ).
  • the width WQ of the region overlapping with the EL layer 112Q is preferably larger than the distance SE.
  • the width W P and the width W Q are preferably 2000 nm or less, preferably 1000 nm or less, more preferably 500 nm or less, still more preferably 300 nm or less, still more preferably 200 nm or less, and still more preferably 150 nm or less.
  • each of the width W P and the width W Q is 300 nm or less.
  • the sum of the width W P and the width W Q of the insulating layer 131 is larger than twice the distance S E .
  • the sum of the width W P , the width W Q , and the distance SE, that is, the width W D of the insulating layer 131 is 1500 nm or less, preferably 1200 nm or less, more preferably 1000 nm or less, further preferably 900 nm or less, and still more preferably 900 nm or less. is preferably 800 nm or less, more preferably 600 nm or less.
  • the width WD is preferably twice or more the distance SE and 1000 nm or less.
  • the distance SE is 20 nm or more and 350 nm or less, preferably 30 nm or more and 300 nm or less, more preferably 40 nm or more and 300 nm or less, still more preferably 50 nm or more and 250 nm or less, still more preferably 50 nm or more and 200 nm or less, still more preferably 50 nm or more and 150 nm or less. is preferred.
  • the distance S E is preferably 50 nm or more and 250 nm or less (for example, 90 nm or thereabouts).
  • a display device with a high aperture ratio is realized by setting the relationship between the insulating layer 131, the EL layer 112P, the EL layer 112Q, the pixel electrode 111P, and the pixel electrode 111Q between two adjacent light emitting elements as described above. can be done.
  • the aperture ratio ratio of effective light emitting area
  • the aperture ratio can be increased to 40% or more, 50% or more, 60% or more, 65% or more, and even 70% or more.
  • FIG. 2A is an example in which the edge of the EL layer 112P does not overlap the pixel electrode 111P and the edge of the EL layer 112Q does not overlap the pixel electrode 111Q.
  • an end portion of the EL layer 112P and an end portion of the EL layer 112Q are located between a pair of pixel electrodes.
  • FIG. 2B shows an example in which the edge of the EL layer 112P overlaps the pixel electrode 111P and the edge of the EL layer 112Q overlaps the pixel electrode 111Q. Further, in plan view, the edge of the pixel electrode 111P and the edge of the pixel electrode 111Q are located between the opposing edges of the two adjacent EL layers.
  • an end portion of one of the pair of EL layers may overlap with the pixel electrode, and an end portion of the other EL layer may not overlap.
  • a structure may be employed in which an end portion of one pixel electrode overlaps with the EL layer and the other end portion does not overlap with the EL layer.
  • the thin films (insulating film, semiconductor film, conductive film, etc.) that make up the display device can be formed by sputtering, chemical vapor deposition (CVD), vacuum deposition, pulsed laser deposition (PLD). ) method, Atomic Layer Deposition (ALD) method, or the like.
  • the CVD method includes a plasma enhanced CVD (PECVD) method, a thermal CVD method, and the like. Also, one of the thermal CVD methods is the metal organic CVD (MOCVD) method.
  • the thin films (insulating films, semiconductor films, conductive films, etc.) that make up the display device can be applied by spin coating, dipping, spray coating, inkjet, dispensing, screen printing, offset printing, doctor knife method, slit coating, roll coating, curtain coating, etc. It can be formed by a method such as coating or knife coating.
  • the thin film when processing the thin film that constitutes the display device, a photolithography method or the like can be used.
  • the thin film may be processed by a nanoimprint method, a sandblast method, a lift-off method, or the like.
  • an island-shaped thin film may be directly formed by a film formation method using a shielding mask such as a metal mask.
  • a photolithography method there are typically the following two methods.
  • One is a method of forming a resist mask on a thin film to be processed, processing the thin film by etching or the like, and removing the resist mask.
  • the other is a method of forming a photosensitive thin film, then performing exposure and development to process the thin film into a desired shape.
  • the light used for exposure can be, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or a mixture of these.
  • ultraviolet rays, KrF laser light, ArF laser light, or the like can also be used.
  • extreme ultraviolet (EUV) light, X-rays, or the like may be used.
  • An electron beam can also be used instead of the light used for exposure.
  • the use of extreme ultraviolet light, X-rays, or electron beams is preferable because extremely fine processing is possible.
  • a photomask is not necessary when exposure is performed by scanning a beam such as an electron beam.
  • a dry etching method, a wet etching method, a sandblasting method, or the like can be used to etch the thin film.
  • substrate 101 a substrate having heat resistance enough to withstand at least heat treatment performed later can be used.
  • a substrate having heat resistance enough to withstand at least heat treatment performed later can be used.
  • a substrate having heat resistance enough to withstand at least heat treatment performed later can be used.
  • a glass substrate, a quartz substrate, a sapphire substrate, a ceramic substrate, an organic resin substrate, or the like can be used.
  • a semiconductor substrate such as a single crystal semiconductor substrate made of silicon, silicon carbide, or the like, a polycrystalline semiconductor substrate, a compound semiconductor substrate such as silicon germanium, or an SOI substrate can be used.
  • the substrate 101 it is preferable to use a substrate in which a semiconductor circuit including a semiconductor element such as a transistor is formed on the above semiconductor substrate or insulating substrate.
  • the semiconductor circuit preferably constitutes, for example, a pixel circuit, a gate line driver circuit (gate driver), a source line driver circuit (source driver), and the like.
  • gate driver gate line driver
  • source driver source driver
  • an arithmetic circuit, a memory circuit, and the like may be configured.
  • a pixel electrode 111R, a pixel electrode 111G, a pixel electrode 111B, and a connection electrode 111C are formed on the substrate 101.
  • a conductive film to be a pixel electrode is formed, a resist mask is formed by photolithography, and unnecessary portions of the conductive film are removed by etching. After that, by removing the resist mask, the pixel electrode 111R, the pixel electrode 111G, and the pixel electrode 111B can be formed.
  • each pixel electrode When using a conductive film that reflects visible light as each pixel electrode, it is preferable to use a material (for example, silver or aluminum) that has as high a reflectance as possible over the entire wavelength range of visible light. Thereby, not only can the light extraction efficiency of the light emitting element be improved, but also the color reproducibility can be improved.
  • a material for example, silver or aluminum
  • an insulating layer 131 is formed to cover end portions of the pixel electrode 111R, the pixel electrode 111G, and the pixel electrode 111B (FIG. 3A).
  • an organic insulating film or an inorganic insulating film can be used as the insulating layer 131.
  • the insulating layer 131 preferably has a tapered end in order to improve the step coverage of the subsequent EL film.
  • the EL film 112Rf has a film containing at least a luminescent compound.
  • one or more of films functioning as an electron injection layer, an electron transport layer, a charge generation layer, a hole transport layer, or a hole injection layer may be stacked.
  • the EL film 112Rf can be formed, for example, by a vapor deposition method, a sputtering method, an inkjet method, or the like. Note that the method is not limited to this, and the film forming method described above can be used as appropriate.
  • the EL film 112Rf is preferably a laminated film in which a hole injection layer, a hole transport layer, a light emitting layer, and an electron transport layer are laminated in this order.
  • a film having an electron-injection layer can be used as the EL layer 114 to be formed later.
  • the light-emitting layer can be prevented from being damaged in a later photolithography step or the like, and a highly reliable light-emitting element can be manufactured.
  • an electron-transporting organic compound can be used for the electron-transporting layer, and a material containing the organic compound and a metal can be used for the electron-injecting layer.
  • the EL film 112Rf is preferably formed so as not to be provided on the connection electrode 111C.
  • the EL film 112Rf is formed by a vapor deposition method (or a sputtering method)
  • a sacrificial film 144a is formed to cover the EL film 112Rf. Also, the sacrificial film 144a is provided in contact with the upper surface of the connection electrode 111C.
  • the sacrificial film 144a a film having high resistance to the etching process of each EL film such as the EL film 112Rf, that is, a film having a high etching selectivity can be used. Also, the sacrificial film 144a can be formed using a film having a high etching selectivity with respect to a protective film such as a protective film 146a which will be described later. Furthermore, the sacrificial film 144a can be a film that can be removed by wet etching that causes little damage to each EL film.
  • the sacrificial film 144a for example, an inorganic film such as a metal film, an alloy film, a metal oxide film, a semiconductor film, or an inorganic insulating film can be used.
  • the sacrificial film 144a can be formed by various film formation methods such as a sputtering method, a vapor deposition method, a CVD method, and an ALD method.
  • the sacrificial film 144a that is directly formed over the EL film 112Rf is preferably formed using the ALD method.
  • the sacrificial film 144a for example, metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, and tantalum, or the metal materials can be used.
  • metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, and tantalum, or the metal materials can be used.
  • a low melting point material such as aluminum or silver.
  • a metal oxide such as indium gallium zinc oxide (In--Ga--Zn oxide, also referred to as IGZO) can be used.
  • indium oxide, indium zinc oxide (In—Zn oxide), indium tin oxide (In—Sn oxide), indium titanium oxide (In—Ti oxide), indium tin zinc oxide (In—Sn -Zn oxide), indium titanium zinc oxide (In-Ti-Zn oxide), indium gallium tin zinc oxide (In-Ga-Sn-Zn oxide), and the like can be used.
  • indium tin oxide containing silicon or the like can be used.
  • element M is aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten , or one or more selected from magnesium
  • M is preferably one or more selected from gallium, aluminum, and yttrium.
  • Inorganic insulating materials such as aluminum oxide, hafnium oxide, and silicon oxide can be used as the sacrificial film 144a.
  • the sacrificial film 144a it is preferable to use a material that can be dissolved in a chemically stable solvent at least for the film positioned at the top of the EL film 112Rf.
  • a material that dissolves in water or alcohol can be suitably used for the sacrificial film 144a.
  • a solvent such as water or alcohol
  • the solvent can be removed at a low temperature in a short time by performing heat treatment in a reduced pressure atmosphere, so that thermal damage to the EL film 112Rf can be reduced, which is preferable.
  • wet film formation methods that can be used to form the sacrificial film 144a include spin coating, dipping, spray coating, inkjet, dispensing, screen printing, offset printing, doctor knife method, slit coating, roll coating, curtain coating, and knife coating. There are coats, etc.
  • an organic material such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin can be used.
  • PVA polyvinyl alcohol
  • polyvinyl butyral polyvinylpyrrolidone
  • polyethylene glycol polyglycerin
  • pullulan polyethylene glycol
  • pullulan polyglycerin
  • pullulan water-soluble cellulose
  • alcohol-soluble polyamide resin water-soluble polyamide resin
  • the protective film 146a is a film used as a hard mask when etching the sacrificial film 144a later. Further, the sacrificial film 144a is exposed when the protective film 146a is processed later. Therefore, the sacrificial film 144a and the protective film 146a are selected from a combination of films having a high etching selectivity. Therefore, a film that can be used for the protective film 146a can be selected according to the etching conditions for the sacrificial film 144a and the etching conditions for the protective film 146a.
  • a gas containing fluorine also referred to as a fluorine-based gas
  • An alloy containing molybdenum and niobium, an alloy containing molybdenum and tungsten, or the like can be used for the protective film 146a.
  • a film capable of obtaining a high etching selectivity that is, capable of slowing the etching rate
  • metal oxide films such as IGZO and ITO.
  • the protective film 146a is not limited to this, and can be selected from various materials according to the etching conditions for the sacrificial film 144a and the etching conditions for the protective film 146a. For example, it can be selected from films that can be used for the sacrificial film 144a.
  • a nitride film for example, can be used as the protective film 146a.
  • nitrides such as silicon nitride, aluminum nitride, hafnium nitride, titanium nitride, tantalum nitride, tungsten nitride, gallium nitride, and germanium nitride can also be used.
  • an oxide film can be used as the protective film 146a.
  • an oxide film or an oxynitride film such as silicon oxide, silicon oxynitride, aluminum oxide, aluminum oxynitride, hafnium oxide, or hafnium oxynitride can be used.
  • an inorganic insulating material such as aluminum oxide, hafnium oxide, or silicon oxide formed by an ALD method
  • an indium gallium zinc oxide In—Ga—Zn oxide
  • a metal oxide containing indium such as an oxide (also referred to as IGZO).
  • an organic film that can be used for the EL film 112Rf or the like may be used as the protective film 146a.
  • the same organic film as used for the EL film 112Rf, the EL film 112Gf, or the EL film 112Bf can be used for the protective film 146a.
  • a deposition apparatus can be used in common with the EL film 112Rf and the like, which is preferable.
  • a resist mask 143a is formed on the protective film 146a at a position overlapping with the pixel electrode 111R and at a position overlapping with the connection electrode 111C (FIG. 3C).
  • the resist mask 143a can use a resist material containing a photosensitive resin, such as a positive resist material or a negative resist material.
  • the resist mask 143a is formed on the sacrificial film 144a without the protective film 146a, if a defect such as a pinhole exists in the sacrificial film 144a, the solvent of the resist material dissolves the EL film 112Rf. There is a risk of Such a problem can be prevented by using the protective film 146a.
  • the resist mask 143a may be formed directly on the sacrificial film 144a without using the protective film 146a.
  • etching the protective film 146a it is preferable to use etching conditions with a high selectivity so that the sacrificial film 144a is not removed by the etching.
  • Etching of the protective film 146a can be performed by wet etching or dry etching. By using dry etching, reduction of the pattern of the protective film 146a can be suppressed.
  • the removal of the resist mask 143a can be performed by wet etching or dry etching.
  • the resist mask 143a is preferably removed by dry etching (also referred to as plasma ashing) using an oxygen gas as an etching gas.
  • the resist mask 143a is removed while the EL film 112Rf is covered with the sacrificial film 144a, the effect on the EL film 112Rf is suppressed.
  • the EL film 112Rf is exposed to oxygen, the electrical characteristics may be adversely affected, so it is suitable for etching using oxygen gas such as plasma ashing.
  • Etching of the sacrificial film 144a can be performed by wet etching or dry etching, but dry etching is preferable because pattern shrinkage can be suppressed.
  • Etching the EL film 112Rf and the protective layer 147a by the same treatment is preferable because the process can be simplified and the manufacturing cost of the display device can be reduced.
  • the EL film 112Rf is preferably etched by dry etching using an etching gas that does not contain oxygen as its main component.
  • Etching gases containing no oxygen as a main component include, for example, noble gases such as CF 4 , C 4 F 8 , SF 6 , CHF 3 , Cl 2 , H 2 O, BCl 3 , H 2 and He.
  • a mixed gas of the above gas and a diluent gas that does not contain oxygen can be used as an etching gas.
  • the etching of the EL film 112Rf and the etching of the protective layer 147a may be performed separately. At this time, the EL film 112Rf may be etched first, or the protective layer 147a may be etched first.
  • the EL layer 112R and the connection electrode 111C are covered with the sacrificial layer 145a.
  • the above description of the EL film 112Rf can be used.
  • a sacrificial film 144b is formed on the EL film 112Gf.
  • the sacrificial film 144b can be formed by a method similar to that of the sacrificial film 144a.
  • the sacrificial film 144b preferably uses the same material as the sacrificial film 144a.
  • a sacrificial film 144b is simultaneously formed on the connection electrode 111C to cover the sacrificial layer 145a.
  • a protective film 146b is formed on the sacrificial film 144b.
  • the protective film 146b can be formed by the same method as the protective film 146a. In particular, it is preferable to use the same material as the protective film 146a for the protective film 146b.
  • a resist mask 143b is formed on the protective film 146b in a region overlapping with the pixel electrode 111G and a region overlapping with the connection electrode 111C (FIG. 4A).
  • the resist mask 143b can be formed by a method similar to that of the resist mask 143a.
  • the description of the protective film 146a can be used.
  • the above description of the sacrificial film 144a can be used.
  • the description of the EL film 112Rf and the protective layer 147a can be used.
  • the EL layer 112R is protected by the sacrificial layer 145a, it can be prevented from being damaged by the etching process of the EL film 112Gf.
  • the strip-shaped EL layer 112R and the strip-shaped EL layer 112G can be separately manufactured with high positional accuracy.
  • the EL layer 112G After forming the EL layer 112G, the EL film 112Bf, the sacrificial film 144c, the protective film 146c, and the resist mask 143c (all not shown) are formed in order. Subsequently, after etching the protective film 146c to form a protective layer 147c (not shown), the resist mask 143c is removed. Subsequently, the sacrificial layer 144c is etched to form a sacrificial layer 145c. After that, the protective layer 147c and the EL film 112Bf are etched to form the strip-shaped EL layer 112B.
  • a sacrificial layer 145c is also formed on the connection electrode 111C at the same time.
  • a sacrificial layer 145a, a sacrificial layer 145b, and a sacrificial layer 145c are stacked on the connection electrode 111C.
  • the sacrificial layer 145a, the sacrificial layer 145b, and the sacrificial layer 145c can be removed by wet etching or dry etching. At this time, it is preferable to use a method that damages the EL layer 112R, the EL layer 112G, and the EL layer 112B as little as possible. In particular, it is preferable to use wet etching. For example, wet etching using a tetramethylammonium hydroxide aqueous solution (TMAH), dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixed liquid thereof is preferably used.
  • TMAH tetramethylammonium hydroxide aqueous solution
  • a solvent such as water or alcohol.
  • various alcohols such as ethyl alcohol, methyl alcohol, isopropyl alcohol (IPA), or glycerin can be used as the alcohol capable of dissolving the sacrificial layer 145a, the sacrificial layer 145b, and the sacrificial layer 145c.
  • drying treatment is performed in order to remove water contained inside the EL layers 112R, 112G, and 112B and water adsorbed to the surfaces thereof.
  • heat treatment is preferably performed in an inert gas atmosphere or a reduced pressure atmosphere.
  • the heat treatment can be performed at a substrate temperature of 50° C. to 200° C., preferably 60° C. to 150° C., more preferably 70° C. to 120° C.
  • a reduced-pressure atmosphere is preferable because drying can be performed at a lower temperature.
  • the EL layer 112R, the EL layer 112G, and the EL layer 112B can be produced separately.
  • the EL layer 114 is formed to cover the EL layer 112R, the EL layer 112G, and the EL layer 112B.
  • the EL layer 114 can be formed by the same method as the EL film 112Rf. When the EL layer 114 is formed by vapor deposition, it is preferable to use a shielding mask so that the EL layer 114 is not formed on the connection electrode 111C.
  • the common electrode 113 can be formed by a film forming method such as vapor deposition or sputtering. Alternatively, a film formed by an evaporation method and a film formed by a sputtering method may be stacked. At this time, it is preferable to form the common electrode 113 so as to include the region where the EL layer 114 is formed. That is, a structure in which an end portion of the EL layer 114 overlaps with the common electrode 113 can be employed.
  • the common electrode 113 is preferably formed using a shielding mask.
  • the common electrode 113 is electrically connected to the connection electrode 111C outside the display area.
  • a protective layer 121 is formed over the common electrode 113 .
  • a sputtering method, a PECVD method, or an ALD method is preferably used for forming the inorganic insulating film used for the protective layer 121 .
  • the ALD method is preferable because it has excellent step coverage and hardly causes defects such as pinholes.
  • the display device 100 shown in FIGS. 1B and 1C can be manufactured.
  • the common electrode 113 and the EL layer 114 are formed to have different top surface shapes in the above description, they may be formed in the same region, that is, to have the same top surface shape.
  • FIG. 5A shows a schematic cross-sectional view after removing the sacrificial layer in the above.
  • EL layer 114 and common electrode 113 can be formed using the same shielding mask or without using a shielding mask. This can reduce manufacturing costs compared to using different shielding masks.
  • the EL layer 114 is sandwiched between the connection electrode 111C and the common electrode 113 in the connection portion 130 .
  • a protective layer 121 is formed.
  • a protective layer 121 it is preferable to provide a protective layer 121 to cover the edge of the common electrode 113 and the edge of the EL layer 114 . This can effectively prevent impurities such as water or oxygen from diffusing into the EL layer 114 and the interface between the EL layer 114 and the common electrode 113 from the outside.
  • the adhesion between the organic film used for the EL layer and the inorganic insulating film may be low, film peeling occurs due to stress during the manufacturing process where the formation surface is the inorganic insulating film. sometimes. Therefore, it is preferable that the EL layer and the sacrificial layer formed over the EL layer have a structure in which the stress is easily relieved, particularly in a region outside the display portion.
  • FIG. 6A shows a schematic top view of a region outside the display section
  • FIG. 6B shows a schematic cross-sectional view taken along dashed-dotted line P1-Q2 in FIG. 6A
  • FIG. 6B shows a cross section when the dummy layer 151 and the wiring 152 are covered with an insulating layer, and the insulating layer 131, the EL film 112Rf, and the sacrificial layer 145a are laminated on the insulating layer.
  • a dummy layer 151 and a wiring 152 are provided in FIG. 6A.
  • the dummy layer is provided to suppress processing variations such as a planarization process.
  • the wiring 152 is wiring that functions as a power supply line (for example, an anode line or a cathode line).
  • the dummy layer 151 has an island-shaped top surface. A plurality of dummy layers 151 are arranged periodically. As a result, stress is relieved in the portion overlapping with the dummy layer 151, so peeling can be suppressed in this region. On the other hand, the wiring 152 has a large area over a wide area, and the stress of the film provided thereover is less likely to be relaxed.
  • FIG. 6C shows a schematic top view in which the wiring 152 has a different shape from the above. Also, FIG. 6D is a schematic cross-sectional view taken along dashed-dotted line P2-Q2 in FIG. 6C.
  • Configuration example 2 A configuration example of a display device that is partially different from configuration example 1 will be described below. In the following, explanations of parts that overlap with the above may be omitted.
  • a display device 100A shown in FIGS. 7A to 7D is mainly different from the display device 100 in that the shapes of the EL layer 114 and the common electrode 113 are different.
  • the EL layer 112R, the EL layer 114, and the common electrode 113 are separated between the two light emitting elements 110R in the Y-direction cross section.
  • the EL layer 112 ⁇ /b>R, the EL layer 114 , and the common electrode 113 have end portions overlapping with the insulating layer 131 .
  • the protective layer 121 is provided to cover the side surfaces of the EL layer 112R, the EL layer 114, and the common electrode 113 in a region overlapping with the insulating layer 131.
  • a concave portion may be formed in a part of the upper surface of the insulating layer 131 .
  • the protective layer 121 is provided along the surface of the concave portion of the insulating layer 131 so as to be in contact therewith. This is preferable because the contact area between the insulating layer 131 and the protective layer 121 is increased and the adhesion between them is improved.
  • FIG. 7A outlines of the common electrode 113 and the EL layer 114 are indicated by dashed lines.
  • the common electrode 113 and the EL layer 114 each have a belt-like top surface shape whose longitudinal direction is parallel to the X direction.
  • the EL layer 112R has an island shape.
  • the light emitting element 110G and the light emitting element 110B can also have the same configuration.
  • FIG. 8A to 8D show cross-sectional schematic diagrams in each step illustrated below.
  • the cross section corresponding to the dashed-dotted line B3-B4 in FIG. 7A and the cross section corresponding to the dashed-dotted line C3-C4 are shown side by side.
  • a plurality of resist masks 143d are formed on the common electrode 113 (FIG. 8B).
  • the resist mask 143d is formed to have a belt-like upper surface shape extending in the X direction.
  • the resist mask 143d overlaps with the pixel electrode 111R.
  • An end portion of the resist mask 143 d is provided on the insulating layer 131 .
  • the etching is preferably performed by dry etching.
  • a part of the insulating layer 131 may be etched during etching of the common electrode 113, the EL layer 114, and the EL layer 112R, and a recess may be formed in the upper portion of the insulating layer 131 as shown in FIG. 8C.
  • a portion of the insulating layer 131 not covered with the resist mask 143d may be etched and divided into two.
  • the resist mask 143d is removed.
  • the removal of the resist mask 143d can be performed by wet etching or dry etching.
  • a protective layer 121 is formed (FIG. 8D).
  • the protective layer 121 is provided to cover the side surface of the common electrode 113, the side surface of the EL layer 114, and the side surface of the EL layer 112R. Moreover, the protective layer 121 is preferably provided in contact with the upper surface of the insulating layer 131 .
  • a gap (also referred to as gap, space, etc.) 122 may be formed above the insulating layer 131 when the protective layer 121 is formed.
  • the air gap 122 may be under reduced pressure or at atmospheric pressure. It may also contain a gas such as air, nitrogen, or a noble gas, or a deposition gas used for deposition of the protective layer 121 .
  • the resist mask 143 d is directly formed on the common electrode 113 here, a film functioning as a hard mask may be provided on the common electrode 113 .
  • a hard mask is formed using the resist mask 143d as a mask, and after the resist mask is removed, the common electrode 113, the EL layer 114, the EL layer 112R, and the like can be etched using the hard mask as a mask. At this time, the hard mask may be removed or left.
  • FIG. 9A and 9B show schematic cross-sectional views of the display device 100B.
  • a top view of the display device 100B is similar to FIG. 1A.
  • 9A corresponds to the cross section in the X direction
  • FIG. 9B corresponds to the cross section in the Y direction.
  • the display device 100B mainly differs from the display device 100 in that it does not have the EL layer 114, which is a common layer.
  • the common electrode 113 is provided in contact with the upper surfaces of the EL layer 112R, the EL layer 112G, and the EL layer 112B.
  • the light-emitting element 110R, the light-emitting element 110G, and the light-emitting element 110B can each have a completely different stacked structure, which increases the choice of materials, thereby increasing the degree of freedom in design. can.
  • a display device 100C shown in FIG. 9C is an example in which a slit extending in the X direction is formed in a region of the common electrode 113 overlapping the insulating layer 131, like the display device 100A.
  • the protective layer 121 is provided in contact with the side surface of the common electrode 113 , the side surface of the EL layer 112 ⁇ /b>R, and the upper surface of the insulating layer 131 .
  • a display device 100D shown in FIGS. 10A and 10B is mainly different from the above-described display device 100 in that the configuration of the light-emitting elements is different.
  • the light emitting element 110R has an optical adjustment layer 115R between the pixel electrode 111R and the EL layer 112R.
  • the light emitting element 110G has an optical adjustment layer 115G between the pixel electrode 111G and the EL layer 112G.
  • the light emitting element 110B has an optical adjustment layer 115B between the pixel electrode 111B and the EL layer 112B.
  • the optical adjustment layer 115R, the optical adjustment layer 115G, and the optical adjustment layer 115B each have transparency to visible light.
  • the optical adjustment layer 115R, the optical adjustment layer 115G, and the optical adjustment layer 115B have different thicknesses. Thereby, the optical path length can be varied for each light emitting element.
  • each light emitting element has a so-called microcavity structure (microresonator structure), and light of a specific wavelength is enhanced. Thereby, a display device with improved color purity can be realized.
  • a conductive material that is transparent to visible light can be used for each optical adjustment layer.
  • conductive oxides such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, gallium-containing zinc oxide, silicon-containing indium tin oxide, and silicon-containing indium zinc oxide can be used. .
  • Each optical adjustment layer can be formed after forming the pixel electrode 111R, the pixel electrode 111G, and the pixel electrode 111B and before forming the EL film 112Rf and the like.
  • Each optical adjustment layer may be a conductive film having a different thickness, or may have a single-layer structure, a two-layer structure, a three-layer structure, etc. in order from the thinnest.
  • a display device 100E shown in FIG. 10C is an example in which an optical adjustment layer is applied to the display device 100A.
  • FIG. 10C shows a cross section of two light emitting elements 110G arranged side by side in the Y direction.
  • a display device 100F shown in FIGS. 11A and 11B is mainly different from the display device 100D in that it does not have an optical adjustment layer.
  • the display device 100F is an example of realizing a microcavity structure by the thickness of the EL layer 112R, the EL layer 112G, and the EL layer 112B. By adopting such a structure, it is not necessary to separately provide an optical adjustment layer, so the process can be simplified.
  • the EL layer 112R of the light emitting element 110R emitting light with the longest wavelength is the thickest
  • the EL layer 112B of the light emitting element 110B emitting light with the shortest wavelength is the thinnest.
  • the thickness of each EL layer can be adjusted in consideration of the wavelength of light emitted from each light-emitting element, the optical characteristics of the layers forming the light-emitting element, the electrical characteristics of the light-emitting element, and the like. .
  • a display device 100G shown in FIG. 11C is an example in which a microcavity structure is realized by varying the thickness of the EL layer of the display device 100A.
  • FIG. 11C shows a cross section of two light emitting elements 110G arranged side by side in the Y direction.
  • This embodiment can be implemented by appropriately combining at least part of it with other embodiments described herein.
  • the display device of this embodiment can be a high-definition display device. Therefore, the display device of the present embodiment includes, for example, information terminals (wearable devices) such as a wristwatch type and a bracelet type, devices for VR such as a head-mounted display, devices for AR such as glasses, and the like. It can be used for the display part of wearable equipment.
  • information terminals wearable devices
  • VR such as a head-mounted display
  • AR such as glasses
  • Display module A perspective view of the display module 280 is shown in FIG. 12A.
  • the display module 280 has a display device 400C and an FPC 290 .
  • the display device included in the display module 280 is not limited to the display device 400C, and may be a display device 400D or a display device 400E, which will be described later.
  • the display module 280 has substrates 291 and 292 .
  • the display module 280 has a display section 281 .
  • the display unit 281 is an area for displaying an image in the display module 280, and is an area where light from each pixel provided in the pixel unit 284, which will be described later, can be visually recognized.
  • FIG. 12B shows a perspective view schematically showing the configuration on the substrate 291 side.
  • a circuit section 282 , a pixel circuit section 283 on the circuit section 282 , and a pixel section 284 on the pixel circuit section 283 are stacked on the substrate 291 .
  • a terminal portion 285 for connecting to the FPC 290 is provided on a portion of the substrate 291 that does not overlap with the pixel portion 284 .
  • the terminal portion 285 and the circuit portion 282 are electrically connected by a wiring portion 286 composed of a plurality of wirings.
  • the pixel section 284 has a plurality of periodically arranged pixels 284a. An enlarged view of one pixel 284a is shown on the right side of FIG. 12B.
  • the pixel 284a has light-emitting elements 430a, 430b, and 430c that emit light of different colors.
  • a plurality of light emitting elements may be arranged in a stripe arrangement as shown in FIG. 12B. Since the stripe arrangement can arrange pixel circuits at high density, it is possible to provide a high-definition display device. Also, various arrangement methods such as delta arrangement and pentile arrangement can be applied.
  • the pixel circuit section 283 has a plurality of periodically arranged pixel circuits 283a.
  • One pixel circuit 283a is a circuit that controls light emission of three light emitting elements included in one pixel 284a.
  • One pixel circuit 283a may have a structure in which three circuits for controlling light emission of one light-emitting element are provided.
  • the pixel circuit 283a can have at least one selection transistor, one current control transistor (driving transistor), and a capacitive element for each light emitting element. At this time, a gate signal is input to the gate of the selection transistor, and a source signal is input to either the source or the drain of the selection transistor. This realizes an active matrix display device.
  • the circuit section 282 has a circuit that drives each pixel circuit 283 a of the pixel circuit section 283 .
  • a circuit that drives each pixel circuit 283 a of the pixel circuit section 283 For example, it is preferable to have one or both of a gate line driver circuit and a source line driver circuit.
  • at least one of an arithmetic circuit, a memory circuit, a power supply circuit, and the like may be provided.
  • the FPC 290 functions as wiring for supplying a video signal, power supply potential, or the like to the circuit section 282 from the outside. Also, an IC may be mounted on the FPC 290 .
  • the aperture ratio (effective display area ratio) of the display portion 281 is extremely high. can be higher.
  • the aperture ratio of the display section 281 can be 40% or more and less than 100%, preferably 50% or more and 95% or less, more preferably 60% or more and 95% or less.
  • the pixels 284a can be arranged at an extremely high density, and the definition of the display portion 281 can be extremely high.
  • pixels 284a may be arranged with a resolution of 2000 ppi or more, preferably 3000 ppi or more, more preferably 5000 ppi or more, and still more preferably 6000 ppi or more, and 20000 ppi or less, or 30000 ppi or less. preferable.
  • a display module 280 Since such a display module 280 has extremely high definition, it can be suitably used for devices for VR such as head-mounted displays, or glasses-type devices for AR. For example, even in the case of a configuration in which the display portion of the display module 280 is viewed through a lens, the display module 280 has an extremely high-definition display portion 281, so pixels cannot be viewed even if the display portion is enlarged with the lens. , a highly immersive display can be performed. Moreover, the display module 280 is not limited to this, and can be suitably used for electronic equipment having a relatively small display unit. For example, it can be suitably used for a display part of a wearable electronic device such as a wristwatch.
  • Display device 400C A display device 400C illustrated in FIG.
  • the substrate 301 corresponds to the substrate 291 in FIGS. 12A and 12B.
  • a laminated structure 401 from the substrate 301 to the insulating layer 255 corresponds to the substrate 101 in the first embodiment.
  • a transistor 310 is a transistor having a channel formation region in the substrate 301 .
  • the substrate 301 for example, a semiconductor substrate such as a single crystal silicon substrate can be used.
  • Transistor 310 includes a portion of substrate 301 , conductive layer 311 , low resistance region 312 , insulating layer 313 and insulating layer 314 .
  • the conductive layer 311 functions as a gate electrode.
  • An insulating layer 313 is located between the substrate 301 and the conductive layer 311 and functions as a gate insulating layer.
  • the low-resistance region 312 is a region in which the substrate 301 is doped with impurities and functions as either a source or a drain.
  • the insulating layer 314 is provided to cover the side surface of the conductive layer 311 and functions as an insulating layer.
  • a device isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301 .
  • An insulating layer 261 is provided to cover the transistor 310 , and a capacitor 240 is provided over the insulating layer 261 .
  • the capacitor 240 has a conductive layer 241, a conductive layer 245, and an insulating layer 243 positioned therebetween.
  • the conductive layer 241 functions as one electrode of the capacitor 240
  • the conductive layer 245 functions as the other electrode of the capacitor 240
  • the insulating layer 243 functions as the dielectric of the capacitor 240 .
  • the conductive layer 241 is provided on the insulating layer 261 and embedded in the insulating layer 254 .
  • Conductive layer 241 is electrically connected to one of the source or drain of transistor 310 by plug 271 embedded in insulating layer 261 .
  • An insulating layer 243 is provided over the conductive layer 241 .
  • the conductive layer 245 is provided in a region overlapping with the conductive layer 241 with the insulating layer 243 provided therebetween.
  • An insulating layer 255 is provided to cover the capacitor 240, and light emitting elements 430a, 430b, 430c, etc. are provided on the insulating layer 255.
  • a protective layer 416 is provided on the light emitting elements 430 a , 430 b , and 430 c , and a substrate 420 is attached to the upper surface of the protective layer 416 with a resin layer 419 .
  • Substrate 420 corresponds to substrate 292 in FIG. 12A.
  • the pixel electrode of the light-emitting element is electrically connected to one of the source and drain of the transistor 310 by a plug 256 embedded in the insulating layer 255, a conductive layer 241 embedded in the insulating layer 254, and a plug 271 embedded in the insulating layer 261. properly connected.
  • Display device 400D A display device 400D shown in FIG. 14 is mainly different from the display device 400C in that the transistor configuration is different. Note that the description of the same parts as the display device 400C may be omitted.
  • the transistor 320 is a transistor in which a metal oxide (also referred to as an oxide semiconductor) is applied to a semiconductor layer in which a channel is formed.
  • a metal oxide also referred to as an oxide semiconductor
  • the transistor 320 has a semiconductor layer 321 , an insulating layer 323 , a conductive layer 324 , a pair of conductive layers 325 , an insulating layer 326 , and a conductive layer 327 .
  • the substrate 331 corresponds to the substrate 291 in FIGS. 12A and 12B.
  • a laminated structure 401 from the substrate 331 to the insulating layer 255 corresponds to the substrate 101 in the first embodiment.
  • the substrate 331 an insulating substrate or a semiconductor substrate can be used.
  • An insulating layer 332 is provided on the substrate 331 .
  • the insulating layer 332 functions as a barrier layer that prevents impurities such as water or hydrogen from diffusing from the substrate 331 into the transistor 320 and oxygen from the semiconductor layer 321 toward the insulating layer 332 side.
  • a film into which hydrogen or oxygen is less likely to diffuse than a silicon oxide film such as an aluminum oxide film, a hafnium oxide film, or a silicon nitride film, can be used.
  • a conductive layer 327 is provided over the insulating layer 332 , and an insulating layer 326 is provided to cover the conductive layer 327 .
  • the conductive layer 327 functions as a first gate electrode of the transistor 320, and part of the insulating layer 326 functions as a first gate insulating layer.
  • An oxide insulating film such as a silicon oxide film is preferably used for at least a portion of the insulating layer 326 that is in contact with the semiconductor layer 321 .
  • the upper surface of the insulating layer 326 is preferably planarized.
  • the semiconductor layer 321 is provided on the insulating layer 326 .
  • the semiconductor layer 321 preferably includes a metal oxide (also referred to as an oxide semiconductor) film having semiconductor characteristics. Details of materials that can be suitably used for the semiconductor layer 321 will be described later.
  • a pair of conductive layers 325 are provided on and in contact with the semiconductor layer 321 and function as a source electrode and a drain electrode.
  • An insulating layer 328 is provided to cover the top and side surfaces of the pair of conductive layers 325, the side surface of the semiconductor layer 321, and the like, and the insulating layer 264 is provided over the insulating layer 328.
  • the insulating layer 328 functions as a barrier layer that prevents impurities such as water or hydrogen from diffusing into the semiconductor layer 321 from the insulating layer 264 or the like and oxygen from leaving the semiconductor layer 321 .
  • an insulating film similar to the insulating layer 332 can be used as the insulating layer 328.
  • An opening reaching the semiconductor layer 321 is provided in the insulating layer 328 and the insulating layer 264 .
  • the insulating layer 323 and the conductive layer 324 are buried in contact with the side surfaces of the insulating layer 264 , the insulating layer 328 , and the conductive layer 325 and the top surface of the semiconductor layer 321 .
  • the conductive layer 324 functions as a second gate electrode, and the insulating layer 323 functions as a second gate insulating layer.
  • the top surface of the conductive layer 324, the top surface of the insulating layer 323, and the top surface of the insulating layer 264 are planarized so that their heights are approximately the same, and the insulating layers 329 and 265 are provided to cover them. .
  • the insulating layers 264 and 265 function as interlayer insulating layers.
  • the insulating layer 329 functions as a barrier layer that prevents impurities such as water or hydrogen from diffusing into the transistor 320 from the insulating layer 265 or the like.
  • an insulating film similar to the insulating layers 328 and 332 can be used.
  • a plug 274 electrically connected to one of the pair of conductive layers 325 is provided so as to be embedded in the insulating layers 265 , 329 and 264 .
  • the plug 274 includes a conductive layer 274a that covers the side surfaces of the openings of the insulating layers 265, the insulating layers 329, the insulating layers 264, and the insulating layer 328 and part of the top surface of the conductive layer 325, and the conductive layer 274a. It is preferable to have a conductive layer 274b in contact with the top surface. At this time, a conductive material into which hydrogen and oxygen are difficult to diffuse is preferably used for the conductive layer 274a.
  • the configuration from the insulating layer 254 to the substrate 420 in the display device 400D is similar to that of the display device 400C.
  • a display device 400E illustrated in FIG. 15 has a structure in which a transistor 310 in which a channel is formed over a substrate 301 and a transistor 320 including a metal oxide in a semiconductor layer in which the channel is formed are stacked. Note that descriptions of portions similar to those of the display devices 400C and 400D may be omitted.
  • An insulating layer 261 is provided to cover the transistor 310 , and a conductive layer 251 is provided over the insulating layer 261 .
  • An insulating layer 262 is provided to cover the conductive layer 251 , and the conductive layer 252 is provided over the insulating layer 262 .
  • the conductive layers 251 and 252 each function as wirings.
  • An insulating layer 263 and an insulating layer 332 are provided to cover the conductive layer 252 , and the transistor 320 is provided over the insulating layer 332 .
  • An insulating layer 265 is provided to cover the transistor 320 and a capacitor 240 is provided over the insulating layer 265 . Capacitor 240 and transistor 320 are electrically connected by plug 274 .
  • the transistor 320 can be used as a transistor forming a pixel circuit. Further, the transistor 310 can be used as a transistor forming a pixel circuit or a transistor forming a driver circuit (a gate line driver circuit or a source line driver circuit) for driving the pixel circuit. Further, the transistors 310 and 320 can be used as transistors included in various circuits such as an arithmetic circuit and a memory circuit.
  • a pixel circuit not only a pixel circuit but also a driver circuit and the like can be formed directly under the light-emitting element, so that the size of the display device can be reduced compared to the case where the driver circuit is provided around the display region. becomes possible.
  • This embodiment can be implemented by appropriately combining at least part of it with other embodiments described herein.
  • a device manufactured using a metal mask or FMM may be referred to as a device with an MM (metal mask) structure.
  • a device manufactured without using a metal mask or FMM may be referred to as a device with an MML (metal maskless) structure.
  • a structure in which a light-emitting layer is separately formed or a light-emitting layer is separately painted in each color light-emitting device is referred to as SBS (Side By Side) structure.
  • SBS Side By Side
  • a light-emitting device capable of emitting white light is sometimes referred to as a white light-emitting device.
  • the white light-emitting device can be combined with a colored layer (for example, a color filter) to form a full-color display device.
  • light-emitting devices can be broadly classified into single structures and tandem structures.
  • a single-structure device preferably has one light-emitting unit between a pair of electrodes, and the light-emitting unit preferably includes one or more light-emitting layers.
  • the light-emitting unit preferably includes one or more light-emitting layers.
  • the luminescent color of the first luminescent layer and the luminescent color of the second luminescent layer have a complementary color relationship, it is possible to obtain a configuration in which the entire light emitting device emits white light.
  • a tandem structure device preferably has two or more light-emitting units between a pair of electrodes, and each light-emitting unit preferably includes one or more light-emitting layers.
  • each light-emitting unit preferably includes one or more light-emitting layers.
  • a structure in which white light emission is obtained by combining light from the light emitting layers of a plurality of light emitting units may be employed. Note that the structure for obtaining white light emission is the same as the structure of the single structure.
  • the white light emitting device when comparing the white light emitting device (single structure or tandem structure) and the light emitting device having the SBS structure, the light emitting device having the SBS structure can consume less power than the white light emitting device. If it is desired to keep power consumption low, it is preferable to use a light-emitting device with an SBS structure. On the other hand, the white light emitting device is preferable because the manufacturing process is simpler than that of the SBS structure light emitting device, so that the manufacturing cost can be lowered or the manufacturing yield can be increased.
  • the light emitting device has an EL layer 23 between a pair of electrodes (lower electrode 21, upper electrode 25).
  • the EL layer 23 can be composed of a plurality of layers such as a layer 4420, a light-emitting layer 4411, and a layer 4430.
  • the layer 4420 can have, for example, a layer containing a substance with high electron-injection properties (electron-injection layer) and a layer containing a substance with high electron-transport properties (electron-transporting layer).
  • the light-emitting layer 4411 contains, for example, a light-emitting compound.
  • Layer 4430 can have, for example, a layer containing a substance with high hole-injection properties (hole-injection layer) and a layer containing a substance with high hole-transport properties (hole-transport layer).
  • a structure having a layer 4420, a light-emitting layer 4411, and a layer 4430 provided between a pair of electrodes can function as a single light-emitting unit, and the structure of FIG. 16A is called a single structure in this specification.
  • FIG. 16B is a modification of the EL layer 23 included in the light emitting element 20 shown in FIG. 16A.
  • the light-emitting element 20 shown in FIG. It has a layer 4420-1 on 4411, a layer 4420-2 on layer 4420-1, and an upper electrode 25 on layer 4420-2.
  • the layer 4430-1 functions as a hole injection layer
  • the layer 4430-2 functions as a hole transport layer
  • the layer 4420-1 functions as an electron Functioning as a transport layer
  • layer 4420-2 functions as an electron injection layer.
  • layer 4430-1 functions as an electron injection layer
  • layer 4430-2 functions as an electron transport layer
  • layer 4420-1 functions as a hole transport layer.
  • a configuration in which a plurality of light-emitting layers (light-emitting layers 4411, 4412, and 4413) are provided between layers 4420 and 4430 as shown in FIG. 16C is also a variation of the single structure.
  • tandem structure a structure in which a plurality of light emitting units (EL layers 23a and 23b) are connected in series via an intermediate layer (charge generation layer) 4440 is referred to herein as a tandem structure.
  • the configuration as shown in FIG. 16D is referred to as a tandem structure, but the configuration is not limited to this, and for example, the tandem structure may be referred to as a stack structure. Note that a light-emitting element capable of emitting light with high luminance can be obtained by adopting a tandem structure.
  • the layers 4420 and 4430 may have a laminated structure consisting of two or more layers as shown in FIG. 16B.
  • the emission color of the light-emitting element can be red, green, blue, cyan, magenta, yellow, white, or the like, depending on the material forming the EL layer 23 . Further, the color purity can be further enhanced by providing the light-emitting element with a microcavity structure.
  • a light-emitting element that emits white light preferably has a structure in which two or more kinds of light-emitting substances are contained in the light-emitting layer.
  • two or more light-emitting substances may be selected so that the light emission of each light-emitting substance has a complementary color relationship.
  • a light-emitting element that emits white light as a whole can be obtained.
  • the light-emitting layer preferably contains two or more light-emitting substances that emit light such as R (red), G (green), B (blue), Y (yellow), and O (orange).
  • R red
  • G green
  • B blue
  • Y yellow
  • O orange
  • a light-emitting element has at least a light-emitting layer. Further, in the light-emitting element, layers other than the light-emitting layer include 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, an electron-blocking material, and a substance with a high electron-injection property.
  • a layer containing a substance, a bipolar substance (a substance with high electron-transport properties and high hole-transport properties), or the like may be further included.
  • Both low-molecular-weight compounds and high-molecular-weight compounds can be used in the light-emitting device, and inorganic compounds may be included.
  • Each of the layers constituting the light-emitting device can be 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.
  • the light-emitting device may have one or more layers selected from a hole-injection layer, a hole-transport layer, a hole-blocking layer, an electron-blocking layer, an electron-transporting layer, and an electron-injecting layer, in addition to the light-emitting layer. can.
  • the hole-injecting layer is a layer that injects holes from the anode into the hole-transporting layer, and contains a material with high hole-injecting properties.
  • highly hole-injecting materials include aromatic amine compounds and composite materials containing a hole-transporting material and an acceptor material (electron-accepting material).
  • the hole-transporting layer is a layer that transports holes injected from the anode to the light-emitting layer by means of the hole-injecting layer.
  • a hole-transporting layer is a layer containing a hole-transporting material.
  • the hole-transporting material a substance having a hole mobility of 1 ⁇ 10 ⁇ 6 cm 2 /Vs or more is preferable. Note that substances other than these can be used as long as they have a higher hole-transport property than electron-transport property.
  • hole-transporting materials include ⁇ -electron-rich heteroaromatic compounds (e.g., carbazole derivatives, thiophene derivatives, furan derivatives, etc.), aromatic amines (compounds having an aromatic amine skeleton), and other highly hole-transporting materials. is preferred.
  • ⁇ -electron-rich heteroaromatic compounds e.g., carbazole derivatives, thiophene derivatives, furan derivatives, etc.
  • aromatic amines compounds having an aromatic amine skeleton
  • other highly hole-transporting materials is preferred.
  • the electron-transporting layer is a layer that transports electrons injected from the cathode to the light-emitting layer by the electron-injecting layer.
  • the electron-transporting layer is a layer containing an electron-transporting material.
  • an electron-transporting material a substance having an electron mobility of 1 ⁇ 10 ⁇ 6 cm 2 /Vs or more is preferable. Note that substances other than these substances can be used as long as they have a higher electron-transport property than hole-transport property.
  • electron-transporting materials include metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, metal complexes having a thiazole skeleton, oxadiazole derivatives, triazole derivatives, imidazole derivatives, ⁇ -electron deficient including oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives with quinoline ligands, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, and other nitrogen-containing heteroaromatic compounds
  • a material having a high electron transport property such as a type heteroaromatic compound can be used.
  • the electron injection layer is a layer that injects electrons from the cathode to the electron transport layer, and is a layer that contains a material with high electron injection properties.
  • Alkali metals, alkaline earth metals, or compounds thereof can be used as materials with high electron injection properties.
  • a composite material containing an electron-transporting material and a donor material (electron-donating material) can also be used as a material with high electron-injecting properties.
  • Examples of the electron injection layer include lithium, cesium, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF 2 ), 8-(quinolinolato)lithium (abbreviation: Liq), 2-(2 -pyridyl)phenoratritium (abbreviation: LiPP), 2-(2-pyridyl)-3-pyridinolatritium (abbreviation: LiPPy), 4-phenyl-2-(2-pyridyl)phenoratritium (abbreviation: LiPPP) , lithium oxide (LiO x ), cesium carbonate, etc., alkali metals, alkaline earth metals, or compounds thereof.
  • Liq lithium, cesium, lithium fluoride
  • CsF cesium fluoride
  • CaF 2 calcium fluoride
  • Liq 8-(quinolinolato)lithium
  • LiPP 2-(2 -pyridyl)phenoratritium
  • a material having an electron transport property may be used as the electron injection layer described above.
  • a compound having a lone pair of electrons and an electron-deficient heteroaromatic ring can be used as the electron-transporting material.
  • a compound having at least one of a pyridine ring, diazine ring (pyrimidine ring, pyrazine ring, pyridazine ring), and triazine ring can be used.
  • the lowest unoccupied molecular orbital (LUMO) of the organic compound having an unshared electron pair is preferably -3.6 eV or more and -2.3 eV or less.
  • CV cyclic voltammetry
  • photoelectron spectroscopy optical absorption spectroscopy
  • inverse photoelectron spectroscopy etc. are used to determine the highest occupied molecular orbital (HOMO) level and LUMO level of an organic compound. can be estimated.
  • BPhen 4,7-diphenyl-1,10-phenanthroline
  • NBPhen 2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline
  • HATNA diquinoxalino [2,3-a:2′,3′-c]phenazine
  • TmPPPyTz 2,4,6-tris[3′-(pyridin-3-yl)biphenyl-3-yl]-1,3 , 5-triazine
  • TmPPPyTz 2,4,6-tris[3′-(pyridin-3-yl)biphenyl-3-yl]-1,3 , 5-triazine
  • a light-emitting layer is a layer containing a light-emitting substance.
  • the emissive layer can have one or more emissive materials.
  • a substance exhibiting emission colors such as blue, purple, violet, green, yellow-green, yellow, orange, and red is used as appropriate.
  • a substance that emits near-infrared light can be used as the light-emitting substance.
  • Examples of light-emitting substances include fluorescent materials, phosphorescent materials, TADF materials, and quantum dot materials.
  • fluorescent materials include pyrene derivatives, anthracene derivatives, triphenylene derivatives, fluorene derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, dibenzoquinoxaline derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthrene derivatives, and naphthalene derivatives. be done.
  • Examples of phosphorescent materials include organometallic complexes (especially iridium complexes) having a 4H-triazole skeleton, 1H-triazole skeleton, imidazole skeleton, pyrimidine skeleton, pyrazine skeleton, or pyridine skeleton, and phenylpyridine derivatives having an electron-withdrawing group.
  • organometallic complexes especially iridium complexes
  • platinum complexes, rare earth metal complexes, etc. which are used as ligands, can be mentioned.
  • the light-emitting layer may contain one or more organic compounds (host material, assist material, etc.) in addition to the light-emitting substance (guest material).
  • One or both of a hole-transporting material and an electron-transporting material can be used as the one or more organic compounds.
  • Bipolar materials or TADF materials may also be used as one or more organic compounds.
  • the light-emitting layer preferably includes, for example, a phosphorescent material and a combination of a hole-transporting material and an electron-transporting material that easily form an exciplex.
  • ExTET Exciplex-Triplet Energy Transfer
  • a combination that forms an exciplex exhibiting light emission that overlaps with the wavelength of the absorption band on the lowest energy side of the light-emitting substance energy transfer becomes smooth and light emission can be efficiently obtained. With this configuration, high efficiency, low-voltage driving, and long life of the light-emitting device can be realized at the same time.
  • This embodiment can be implemented by appropriately combining at least part of it with other embodiments described herein.
  • FIG. 17A An example of a circuit diagram of the pixel unit 70 is shown in FIG. 17A.
  • the pixel unit 70 is composed of two pixels (pixel 70a and pixel 70b). Wiring 51a, wiring 51b, wiring 52a, wiring 52b, wiring 52c, wiring 52d, wiring 53a, wiring 53b, wiring 53c, and the like are connected to the pixel unit .
  • the pixel 70a has a sub-pixel 71a, a sub-pixel 72a, and a sub-pixel 73a.
  • Pixel 70b has sub-pixel 71b, sub-pixel 72b, and sub-pixel 73b.
  • the sub-pixel 71a, the sub-pixel 72a, and the sub-pixel 73a respectively have a pixel circuit 41a, a pixel circuit 42a, and a pixel circuit 43a.
  • the sub-pixel 71b, the sub-pixel 72b, and the sub-pixel 73b respectively have a pixel circuit 41b, a pixel circuit 42b, and a pixel circuit 43b.
  • Each subpixel has a pixel circuit and a display element 60 .
  • the sub-pixel 71a has a pixel circuit 41a and a display element 60.
  • FIG. Here, a case where a light-emitting element such as an organic EL element is used as the display element 60 is shown.
  • the wiring 51a and the wiring 51b each have a function as a gate line.
  • Each of the wirings 52a, 52b, 52c, and 52d functions as a signal line (also referred to as a data line).
  • the wirings 53 a , 53 b , and 53 c have a function of supplying a potential to the display element 60 .
  • the pixel circuit 41a is electrically connected to the wiring 51a, the wiring 52a, and the wiring 53a.
  • the pixel circuit 42a is electrically connected to the wiring 51b, the wiring 52d, and the wiring 53a.
  • the pixel circuit 43a is electrically connected to the wirings 51a, 52b, and 53b.
  • the pixel circuit 41b is electrically connected to the wiring 51b, the wiring 52a, and the wiring 53b.
  • the pixel circuit 42b is electrically connected to the wiring 51a, the wiring 52c, and the wiring 53c.
  • the pixel circuit 43b is electrically connected to the wirings 51b, 52b, and 53c.
  • the number of source lines can be halved compared to the stripe arrangement.
  • the number of terminals of the IC used as the source driver circuit can be reduced by half, and the number of parts can be reduced.
  • pixel circuits corresponding to the same color it is preferable to connect pixel circuits corresponding to the same color to one wiring functioning as a signal line.
  • the correction value may differ greatly for each color. Therefore, by making the pixel circuits connected to one signal line all correspond to the same color, correction can be facilitated.
  • Each pixel circuit also has a transistor 61 , a transistor 62 and a capacitive element 63 .
  • the transistor 61 has a gate electrically connected to the wiring 51a, one of the source and the drain electrically connected to the wiring 52a, and the other of the source and the drain being the gate of the transistor 62 and the capacitor. It is electrically connected to one electrode of 63 .
  • One of the source and the drain of the transistor 62 is electrically connected to one electrode of the display element 60, and the other of the source and the drain is electrically connected to the other electrode of the capacitor 63 and the wiring 53a.
  • the other electrode of the display element 60 is electrically connected to the wiring to which the potential V1 is applied.
  • a wiring connected to the gate of the transistor 61, a wiring connected to one of the source and the drain of the transistor 61, and a wiring connected to the other electrode of the capacitor 63 are connected. It has the same configuration as the pixel circuit 41a except that at least one is different.
  • the transistor 61 functions as a selection transistor.
  • the transistor 62 is connected in series with the display element 60 and has a function of controlling current flowing through the display element 60 .
  • the capacitor 63 has a function of holding the potential of the node to which the gate of the transistor 62 is connected. Note that in the case where leakage current in the off state of the transistor 61, leakage current through the gate of the transistor 62, or the like is extremely small, the capacitor 63 does not have to be intentionally provided.
  • the transistor 62 preferably has a first gate and a second gate electrically connected to each other. With such a structure having two gates, the current that can flow through the transistor 62 can be increased. In particular, it is preferable for a high-definition display device because the current can be increased without increasing the size of the transistor 62, particularly the channel width.
  • the transistor 62 may have one gate. With such a structure, the step of forming the second gate is not required, so the steps can be simplified as compared with the above.
  • the transistor 61 may have two gates. With such a structure, the size of each transistor can be reduced. Further, a structure in which the first gate and the second gate of each transistor are electrically connected to each other can be employed. Alternatively, one gate may be electrically connected to another wiring instead of the other gate. In that case, the threshold voltage of the transistor can be controlled by applying different potentials to the two gates.
  • the electrode electrically connected to the transistor 62 corresponds to the pixel electrode.
  • FIG. 17A shows a configuration in which the electrode electrically connected to the transistor 62 of the display element 60 is the cathode, and the electrode on the opposite side is the anode.
  • transistor 62 is an n-channel transistor. That is, when the transistor 62 is on, the potential applied from the wiring 53a is the source potential; Alternatively, a p-channel transistor may be used as a transistor included in the pixel circuit. Also, the cathode and anode of the display element 60 may be reversed.
  • FIG. 17B is a schematic top view showing an example of a method of arranging each pixel electrode and each wiring in the display area.
  • the wirings 51a and the wirings 51b are arranged alternately.
  • a wiring 52a, a wiring 52b, and a wiring 52c intersecting with the wiring 51a and the wiring 51b are arranged in this order.
  • Each pixel electrode is arranged in a matrix along the extension direction of the wiring 51a and the wiring 51b.
  • the pixel unit 70 includes a pixel 70a and a pixel 70b.
  • the pixel 70a has a pixel electrode 91R1, a pixel electrode 91G1, and a pixel electrode 91B1.
  • the pixel 70b has a pixel electrode 91R2, a pixel electrode 91G2, and a pixel electrode 91B2. Also, the display area of one sub-pixel is positioned inside the pixel electrode of the sub-pixel.
  • the period P can be 1 ⁇ m or more and 150 ⁇ m or less, preferably 2 ⁇ m or more and 120 ⁇ m or less, more preferably 3 ⁇ m or more and 100 ⁇ m or less, further preferably 4 ⁇ m or more and 60 ⁇ m or less. This makes it possible to realize an extremely high-definition display device.
  • the pixel electrode 91R1 and the like are provided so as not to overlap with the wiring 52a and the like functioning as the signal line. As a result, it is possible to prevent the luminance of the display element from changing due to electric noise transmitted through the capacitance between the wiring 52a and the like and the pixel electrode 91R1 and the like, and the potential of the pixel electrode 91R1 and the like varying. .
  • the pixel electrode 91R1 and the like may be provided so as to overlap with the wiring 51a and the like functioning as scanning lines. As a result, the area of the pixel electrode 91R1 can be increased, so that the aperture ratio can be increased.
  • FIG. 17B shows an example in which a part of the pixel electrode 91R1 is arranged so as to overlap with the wiring 51a.
  • the wiring is preferably connected to the pixel circuit of the sub-pixel.
  • the period in which a signal that changes the potential of the wiring 51a or the like is input corresponds to the period in which the data of the sub-pixel is rewritten. , the luminance of the sub-pixel does not change.
  • Example 1 of pixel layout An example layout of the pixel unit 70 will be described below.
  • FIG. 18A shows an example layout of one sub-pixel. Here, for ease of viewing, an example of the state before forming the pixel electrodes is shown.
  • the sub-pixel shown in FIG. 18A has a transistor 61, a transistor 62, and a capacitive element 63.
  • the sub-pixel shown in FIG. The transistor 62 is a transistor having two gates sandwiching a semiconductor layer.
  • the wiring 51 and the gate of one of the transistors 62 are formed by the conductive film located at the bottom.
  • a conductive film formed later forms the gate of the transistor 61 and the other gate of the transistor 62 .
  • a conductive film formed later forms the wiring 52, the source and drain electrodes of each transistor, one electrode of the capacitor 63, and the like.
  • the wiring 53 and the like are formed by the conductive film formed later. Part of the wiring 53 functions as the other electrode of the capacitor 63 .
  • FIG. 18B shows an example layout of the pixel unit 70 using the sub-pixels illustrated in FIG. 18A.
  • each pixel electrode pixel electrode 31a, pixel electrode 31b, pixel electrode 32a, pixel electrode 32b, pixel electrode 33a, pixel electrode 33b
  • display area 22 are also clearly shown.
  • This embodiment can be implemented by appropriately combining at least part of it with other embodiments described herein.
  • the metal oxide preferably contains at least indium or zinc. In particular, it preferably contains indium and zinc. In addition to these, aluminum, gallium, yttrium, tin and the like are preferably contained. In addition, one or more selected from boron, silicon, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, magnesium, cobalt, etc. may be contained. .
  • the metal oxide is formed by sputtering, chemical vapor deposition (CVD) such as metal organic chemical vapor deposition (MOCVD), or atomic layer deposition (ALD). It can be formed by a layer deposition method or the like.
  • CVD chemical vapor deposition
  • MOCVD metal organic chemical vapor deposition
  • ALD atomic layer deposition
  • Crystal structures of oxide semiconductors include amorphous (including completely amorphous), CAAC (c-axis-aligned crystalline), nc (nanocrystalline), CAC (cloud-aligned composite), single crystal, and polycrystal. (poly crystal) and the like.
  • the crystal structure of the film or substrate can be evaluated using an X-ray diffraction (XRD) spectrum.
  • XRD X-ray diffraction
  • it can be evaluated using an XRD spectrum obtained by GIXD (Grazing-Incidence XRD) measurement.
  • GIXD Gram-Incidence XRD
  • the GIXD method is also called a thin film method or a Seemann-Bohlin method.
  • the shape of the peak of the XRD spectrum is almost bilaterally symmetrical.
  • the peak shape of the XRD spectrum is left-right asymmetric.
  • the asymmetric shape of the peaks in the XRD spectra demonstrates the presence of crystals in the film or substrate. In other words, the film or substrate cannot be said to be in an amorphous state unless the shape of the peaks in the XRD spectrum is symmetrical.
  • the crystal structure of the film or substrate can be evaluated by a diffraction pattern (also referred to as a nano beam electron diffraction pattern) observed by nano beam electron diffraction (NBED).
  • a diffraction pattern also referred to as a nano beam electron diffraction pattern
  • NBED nano beam electron diffraction
  • a halo is observed in the diffraction pattern of a quartz glass substrate, and it can be confirmed that the quartz glass is in an amorphous state.
  • a spot-like pattern is observed instead of a halo. Therefore, it is presumed that the IGZO film deposited at room temperature is neither crystalline nor amorphous, but in an intermediate state and cannot be concluded to be in an amorphous state.
  • oxide semiconductors may be classified differently from the above when their structures are focused. For example, oxide semiconductors are classified into single-crystal oxide semiconductors and non-single-crystal oxide semiconductors. Examples of non-single-crystal oxide semiconductors include the above CAAC-OS and nc-OS. Non-single-crystal oxide semiconductors include polycrystalline oxide semiconductors, amorphous-like oxide semiconductors (a-like OS), amorphous oxide semiconductors, and the like.
  • CAAC-OS is an oxide semiconductor that includes a plurality of crystal regions, and the c-axes of the plurality of crystal regions are oriented in a specific direction. Note that the specific direction is the thickness direction of the CAAC-OS film, the normal direction to the formation surface of the CAAC-OS film, or the normal direction to the surface of the CAAC-OS film.
  • a crystalline region is a region having periodicity in atomic arrangement. If the atomic arrangement is regarded as a lattice arrangement, the crystalline region is also a region with a uniform lattice arrangement.
  • CAAC-OS has a region where a plurality of crystal regions are connected in the a-b plane direction, and the region may have strain.
  • the strain refers to a portion where the orientation of the lattice arrangement changes between a region with a uniform lattice arrangement and another region with a uniform lattice arrangement in a region where a plurality of crystal regions are connected. That is, CAAC-OS is an oxide semiconductor that is c-axis oriented and has no obvious orientation in the ab plane direction.
  • each of the plurality of crystal regions is composed of one or more microcrystals (crystals having a maximum diameter of less than 10 nm).
  • the maximum diameter of the crystalline region is less than 10 nm.
  • the size of the crystal region may be about several tens of nanometers.
  • CAAC-OS contains indium (In) and oxygen.
  • a tendency to have a layered crystal structure also referred to as a layered structure in which a layer (hereinafter referred to as an In layer) and a layer containing the element M, zinc (Zn), and oxygen (hereinafter referred to as a (M, Zn) layer) are stacked.
  • the (M, Zn) layer may contain indium.
  • the In layer contains the element M.
  • the In layer may contain Zn.
  • the layered structure is observed as a lattice image in, for example, a high-resolution TEM (Transmission Electron Microscope) image.
  • a plurality of bright points are observed in the electron beam diffraction pattern of the CAAC-OS film.
  • a certain spot and another spot are observed at point-symmetrical positions with respect to the spot of the incident electron beam that has passed through the sample (also referred to as a direct spot) as the center of symmetry.
  • the lattice arrangement in the crystal region is basically a hexagonal lattice, but the unit cell is not always a regular hexagon and may be a non-regular hexagon. Moreover, the distortion may have a lattice arrangement such as a pentagon or a heptagon.
  • the distortion of the lattice arrangement suppresses the formation of grain boundaries. This is because the CAAC-OS can tolerate strain due to the fact that the arrangement of oxygen atoms is not dense in the ab plane direction, the bond distance between atoms changes due to the substitution of metal atoms, and the like. It is considered to be for
  • a crystal structure in which clear grain boundaries are confirmed is called a polycrystal.
  • a grain boundary becomes a recombination center, traps carriers, and is highly likely to cause a decrease in on-current of a transistor, a decrease in field-effect mobility, and the like. Therefore, a CAAC-OS in which no clear grain boundaries are observed is one of crystalline oxides having a crystal structure suitable for a semiconductor layer of a transistor.
  • a structure containing Zn is preferable for forming a CAAC-OS.
  • In--Zn oxide and In--Ga--Zn oxide are preferable because they can suppress the generation of grain boundaries more than In oxide.
  • CAAC-OS is an oxide semiconductor with high crystallinity and no clear crystal grain boundaries. Therefore, it can be said that the decrease in electron mobility due to grain boundaries is less likely to occur in CAAC-OS.
  • a CAAC-OS can be said to be an oxide semiconductor with few impurities and defects (such as oxygen vacancies). Therefore, an oxide semiconductor including CAAC-OS has stable physical properties. Therefore, an oxide semiconductor including CAAC-OS is resistant to heat and has high reliability.
  • CAAC-OS is also stable against high temperatures (so-called thermal budget) in the manufacturing process. Therefore, the use of the CAAC-OS for the OS transistor makes it possible to increase the degree of freedom in the manufacturing process.
  • nc-OS has periodic atomic arrangement in a minute region (eg, a region of 1 nm to 10 nm, particularly a region of 1 nm to 3 nm).
  • the nc-OS has minute crystals.
  • the size of the minute crystal is, for example, 1 nm or more and 10 nm or less, particularly 1 nm or more and 3 nm or less, the minute crystal is also called a nanocrystal.
  • nc-OS does not show regularity in crystal orientation between different nanocrystals. Therefore, no orientation is observed in the entire film.
  • an nc-OS may be indistinguishable from an a-like OS or an amorphous oxide semiconductor depending on the analysis method.
  • an nc-OS film is subjected to structural analysis using an XRD apparatus, out-of-plane XRD measurement using ⁇ /2 ⁇ scanning does not detect a peak indicating crystallinity.
  • an nc-OS film is subjected to electron beam diffraction (also referred to as selected area electron beam diffraction) using an electron beam with a probe diameter larger than that of nanocrystals (for example, 50 nm or more), a diffraction pattern such as a halo pattern is obtained. is observed.
  • an nc-OS film is subjected to electron diffraction (also referred to as nanobeam electron diffraction) using an electron beam with a probe diameter close to or smaller than the size of a nanocrystal (for example, 1 nm or more and 30 nm or less)
  • an electron beam diffraction pattern is obtained in which a plurality of spots are observed within a ring-shaped area centered on the direct spot.
  • An a-like OS is an oxide semiconductor having a structure between an nc-OS and an amorphous oxide semiconductor.
  • An a-like OS has void or low density regions. That is, the a-like OS has lower crystallinity than the nc-OS and CAAC-OS. In addition, the a-like OS has a higher hydrogen concentration in the film than the nc-OS and the CAAC-OS.
  • CAC-OS relates to material composition.
  • CAC-OS is, for example, one structure of a material in which elements constituting a metal oxide are unevenly distributed with a size of 0.5 nm or more and 10 nm or less, preferably 1 nm or more and 3 nm or less, or in the vicinity thereof.
  • the metal oxide one or more metal elements are unevenly distributed, and the region having the metal element has a size of 0.5 nm or more and 10 nm or less, preferably 1 nm or more and 3 nm or less, or a size in the vicinity thereof.
  • the mixed state is also called mosaic or patch.
  • CAC-OS is a structure in which the material is separated into a first region and a second region to form a mosaic shape, and the first region is distributed in the film (hereinafter, also referred to as a cloud shape). ). That is, CAC-OS is a composite metal oxide in which the first region and the second region are mixed.
  • the atomic ratios of In, Ga, and Zn to the metal elements constituting the CAC-OS in the In--Ga--Zn oxide are denoted by [In], [Ga], and [Zn], respectively.
  • the first region is a region where [In] is larger than [In] in the composition of the CAC-OS film.
  • the second region is a region where [Ga] is greater than [Ga] in the composition of the CAC-OS film.
  • the first region is a region in which [In] is larger than [In] in the second region and [Ga] is smaller than [Ga] in the second region.
  • the second region is a region in which [Ga] is larger than [Ga] in the first region and [In] is smaller than [In] in the first region.
  • the first region is a region whose main component is indium oxide, indium zinc oxide, or the like.
  • the second region is a region containing gallium oxide, gallium zinc oxide, or the like as a main component. That is, the first region can be rephrased as a region containing In as a main component. Also, the second region can be rephrased as a region containing Ga as a main component.
  • a clear boundary between the first region and the second region may not be observed.
  • the CAC-OS in the In—Ga—Zn oxide means a region containing Ga as a main component and a region containing In as a main component in a material structure containing In, Ga, Zn, and O. Each region is a mosaic, and refers to a configuration in which these regions exist randomly. Therefore, CAC-OS is presumed to have a structure in which metal elements are unevenly distributed.
  • a CAC-OS can be formed, for example, by a sputtering method under the condition that the substrate is not intentionally heated.
  • a sputtering method one or more selected from an inert gas (typically argon), an oxygen gas, and a nitrogen gas may be used as a deposition gas. good.
  • an inert gas typically argon
  • oxygen gas typically argon
  • a nitrogen gas may be used as a deposition gas. good.
  • the lower the flow rate ratio of the oxygen gas to the total flow rate of the film formation gas during film formation, the better. is preferably 0% or more and 10% or less.
  • a region containing In as a main component is obtained by EDX mapping obtained using energy dispersive X-ray spectroscopy (EDX). It can be confirmed that the (first region) and the region (second region) containing Ga as the main component are unevenly distributed and have a mixed structure.
  • EDX energy dispersive X-ray spectroscopy
  • the first region is a region with higher conductivity than the second region. That is, when carriers flow through the first region, conductivity as a metal oxide is developed. Therefore, by distributing the first region in the form of a cloud in the metal oxide, a high field effect mobility ( ⁇ ) can be realized.
  • the second region is a region with higher insulation than the first region.
  • the leakage current can be suppressed by distributing the second region in the metal oxide.
  • CAC-OS when used for a transistor, the conductivity caused by the first region and the insulation caused by the second region act in a complementary manner to provide a switching function (turning ON/OFF). functions) can be given to the CAC-OS.
  • a part of the material has a conductive function
  • a part of the material has an insulating function
  • the whole material has a semiconductor function.
  • CAC-OS is most suitable for various semiconductor devices including display devices.
  • Oxide semiconductors have a variety of structures, each with different characteristics.
  • An oxide semiconductor of one embodiment of the present invention includes two or more of an amorphous oxide semiconductor, a polycrystalline oxide semiconductor, an a-like OS, a CAC-OS, an nc-OS, and a CAAC-OS. may
  • an oxide semiconductor with low carrier concentration is preferably used for a transistor.
  • the carrier concentration of the oxide semiconductor is 1 ⁇ 10 17 cm ⁇ 3 or less, preferably 1 ⁇ 10 15 cm ⁇ 3 or less, more preferably 1 ⁇ 10 13 cm ⁇ 3 or less, more preferably 1 ⁇ 10 11 cm ⁇ 3 or less. 3 or less, more preferably less than 1 ⁇ 10 10 cm ⁇ 3 and 1 ⁇ 10 ⁇ 9 cm ⁇ 3 or more.
  • the impurity concentration in the oxide semiconductor film may be lowered to lower the defect level density.
  • a low impurity concentration and a low defect level density are referred to as high-purity intrinsic or substantially high-purity intrinsic.
  • an oxide semiconductor with a low carrier concentration is sometimes referred to as a highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor.
  • the trap level density may also be low.
  • the charge trapped in the trap level of the oxide semiconductor takes a long time to disappear, and may behave as if it were a fixed charge. Therefore, a transistor whose channel formation region is formed in an oxide semiconductor with a high trap level density might have unstable electrical characteristics.
  • Impurities include hydrogen, nitrogen, alkali metals, alkaline earth metals, iron, nickel, silicon, and the like.
  • the concentration of silicon or carbon in the oxide semiconductor and the concentration of silicon or carbon in the vicinity of the interface with the oxide semiconductor are 2. ⁇ 10 18 atoms/cm 3 or less, preferably 2 ⁇ 10 17 atoms/cm 3 or less.
  • the concentration of alkali metal or alkaline earth metal in the oxide semiconductor obtained by SIMS is set to 1 ⁇ 10 18 atoms/cm 3 or less, preferably 2 ⁇ 10 16 atoms/cm 3 or less.
  • the nitrogen concentration in the oxide semiconductor obtained by SIMS is less than 5 ⁇ 10 19 atoms/cm 3 , preferably 5 ⁇ 10 18 atoms/cm 3 or less, more preferably 1 ⁇ 10 18 atoms/cm 3 or less. , more preferably 5 ⁇ 10 17 atoms/cm 3 or less.
  • the oxide semiconductor reacts with oxygen that bonds to a metal atom to form water, which may cause oxygen vacancies.
  • oxygen vacancies When hydrogen enters the oxygen vacancies, electrons, which are carriers, may be generated.
  • part of hydrogen may bond with oxygen that bonds with a metal atom to generate an electron, which is a carrier. Therefore, a transistor including an oxide semiconductor containing hydrogen is likely to have normally-on characteristics. Therefore, hydrogen in the oxide semiconductor is preferably reduced as much as possible.
  • the hydrogen concentration obtained by SIMS is less than 1 ⁇ 10 20 atoms/cm 3 , preferably less than 1 ⁇ 10 19 atoms/cm 3 , more preferably less than 5 ⁇ 10 18 atoms/cm. Less than 3 , more preferably less than 1 ⁇ 10 18 atoms/cm 3 .
  • This embodiment can be implemented by appropriately combining at least part of it with other embodiments described herein.
  • An electronic device of this embodiment includes a display device of one embodiment of the present invention.
  • the display device of one embodiment of the present invention can easily have high definition, high resolution, and large size. Therefore, the display device of one embodiment of the present invention can be used for display portions of various electronic devices.
  • the display device of one embodiment of the present invention can be manufactured at low cost, the manufacturing cost of the electronic device can be reduced.
  • Examples of electronic devices include televisions, desktop or notebook personal computers, computer monitors, digital signage, large game machines such as pachinko machines, and other electronic devices with relatively large screens. Examples include cameras, digital video cameras, digital photo frames, mobile phones, mobile game machines, mobile information terminals, and sound reproducing devices.
  • the display device of one embodiment of the present invention can have high definition, it can be suitably used for an electronic device having a relatively small display portion.
  • electronic devices include wristwatch-type and bracelet-type information terminals (wearable devices), VR devices such as head-mounted displays, and glasses-type AR devices that can be worn on the head. equipment and the like.
  • Wearable devices also include devices for SR (Substitutional Reality) and devices for MR (Mixed Reality).
  • a display device of one embodiment of the present invention includes HD (1280 ⁇ 720 pixels), FHD (1920 ⁇ 1080 pixels), WQHD (2560 ⁇ 1440 pixels), WQXGA (2560 ⁇ 1600 pixels), 4K2K (2560 ⁇ 1600 pixels), 3840 ⁇ 2160) and 8K4K (7680 ⁇ 4320 pixels).
  • the resolution it is preferable to set the resolution to 4K2K, 8K4K, or higher.
  • the pixel density (definition) of the display device of one embodiment of the present invention is preferably 300 ppi or more, more preferably 500 ppi or more, 1000 ppi or more, more preferably 2000 ppi or more, more preferably 3000 ppi or more, and 5000 ppi or more.
  • the electronic device of this embodiment can be incorporated along the inner or outer wall of a house or building, or along the curved surface of the interior or exterior of an automobile.
  • the electronic device of this embodiment may have an antenna.
  • An image, information, or the like can be displayed on the display portion by receiving a signal with the antenna.
  • the antenna may be used for contactless power transmission.
  • the electronic device of this embodiment includes sensors (force, displacement, position, velocity, acceleration, angular velocity, number of revolutions, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage , power, radiation, flow, humidity, gradient, vibration, odor or infrared sensing, detection or measurement).
  • the electronic device of this embodiment can have various functions. For example, functions to display various information (still images, moving images, text images, etc.) on the display unit, touch panel functions, calendars, functions to display the date or time, 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.
  • An electronic device 6500 shown in FIG. 19A is a mobile information terminal that can be used as a smartphone.
  • the electronic device 6500 has a housing 6501, a display unit 6502, a power button 6503, a button 6504, a speaker 6505, a microphone 6506, a camera 6507, a light source 6508, and the like.
  • a display portion 6502 has a touch panel function.
  • the display device of one embodiment of the present invention can be applied to the display portion 6502 .
  • FIG. 19B is a schematic cross-sectional view including the end of the housing 6501 on the microphone 6506 side.
  • a light-transmitting protective member 6510 is provided on the display surface side of the housing 6501, and a display panel 6511, an optical member 6512, a touch sensor panel 6513, and a printer are placed in a space surrounded by the housing 6501 and the protective member 6510.
  • a substrate 6517, a battery 6518, and the like are arranged.
  • a display panel 6511, an optical member 6512, and a touch sensor panel 6513 are fixed to the protective member 6510 with an adhesive layer (not shown).
  • a portion of the display panel 6511 is folded back in a region outside the display portion 6502, and the FPC 6515 is connected to the folded portion.
  • An IC6516 is mounted on the FPC6515.
  • the FPC 6515 is connected to terminals provided on the printed circuit board 6517 .
  • a flexible display (flexible display device) of one embodiment of the present invention can be applied to the display panel 6511 . Therefore, an extremely lightweight electronic device can be realized. In addition, since the display panel 6511 is extremely thin, the thickness of the electronic device can be reduced and the large-capacity battery 6518 can be mounted. In addition, by folding back part of the display panel 6511 and arranging a connection portion with the FPC 6515 on the back side of the pixel portion, an electronic device with a narrow frame can be realized.
  • FIG. 20A An example of a television device is shown in FIG. 20A.
  • a television set 7100 has a display portion 7000 incorporated in a housing 7101 .
  • a configuration in which a housing 7101 is supported by a stand 7103 is shown.
  • the display device of one embodiment of the present invention can be applied to the display portion 7000 .
  • the operation of the television apparatus 7100 shown in FIG. 20A can be performed using operation switches provided in the housing 7101 and a separate remote control operation device 7111 .
  • the display portion 7000 may be provided with a touch sensor, and the television device 7100 may be operated by touching the display portion 7000 with a finger or the like.
  • the remote controller 7111 may have a display section for displaying information output from the remote controller 7111 .
  • a channel and a volume can be operated with operation keys or a touch panel provided in the remote controller 7111 , and an image displayed on the display portion 7000 can be operated.
  • the television device 7100 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. 20B shows an example of a notebook personal computer.
  • a notebook personal computer 7200 has a housing 7211, a keyboard 7212, a pointing device 7213, an external connection port 7214, and the like.
  • the display portion 7000 is incorporated in the housing 7211 .
  • the display device of one embodiment of the present invention can be applied to the display portion 7000 .
  • FIGS. 20C and 20D An example of digital signage is shown in FIGS. 20C and 20D.
  • a digital signage 7300 shown in FIG. 20C includes a housing 7301, a display unit 7000, speakers 7303, 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. 20D shows a digital signage 7400 attached to a cylindrical pillar 7401.
  • a digital signage 7400 has a display section 7000 provided along the curved surface of a pillar 7401 .
  • the display device of one embodiment of the present invention can be applied to the display portion 7000 in FIGS. 20C and 20D.
  • the wider the display unit 7000 the more information can be provided at once.
  • the wider the display unit 7000 the more conspicuous it is, and the more effective the advertisement can be, for example.
  • a touch panel By applying a touch panel to the display unit 7000, not only can images or moving images be displayed on the display unit 7000, but also the user can intuitively operate the display unit 7000, which is preferable. Further, when used for providing information such as route information or traffic information, usability can be enhanced by intuitive operation.
  • the digital signage 7300 or digital signage 7400 is preferably capable of cooperating with an information terminal 7311 or 7411 such as a smartphone possessed by the user through wireless communication.
  • advertisement information displayed on the display unit 7000 can be displayed on the screen of the information terminal 7311 or the information terminal 7411 .
  • display on the display portion 7000 can be switched.
  • the digital signage 7300 or the digital signage 7400 can execute a game using the screen of the information terminal 7311 or 7411 as an operation means (controller). This allows an unspecified number of users to simultaneously participate in and enjoy the game.
  • FIG. 21A is a diagram showing the appearance of the camera 8000 with the finder 8100 attached.
  • a camera 8000 has a housing 8001, a display unit 8002, an operation button 8003, a shutter button 8004, and the like.
  • a detachable lens 8006 is attached to the camera 8000 .
  • lens 8006 and housing 8001 may be integrated.
  • the camera 8000 can capture an image by pressing the shutter button 8004 or by touching the display unit 8002 that functions as a touch panel.
  • the housing 8001 has a mount with electrodes, and can be connected to the viewfinder 8100 as well as a strobe device or the like.
  • the viewfinder 8100 has a housing 8101, a display section 8102, buttons 8103, and the like.
  • the housing 8101 is attached to the camera 8000 by mounts that engage the mounts of the camera 8000 .
  • a viewfinder 8100 can display an image or the like received from the camera 8000 on a display portion 8102 .
  • the button 8103 has a function as a power button or the like.
  • the display device of one embodiment of the present invention can be applied to the display portion 8002 of the camera 8000 and the display portion 8102 of the viewfinder 8100 .
  • the camera 8000 having a built-in finder may also be used.
  • FIG. 21B is a diagram showing the appearance of the head mounted display 8200.
  • FIG. 21B is a diagram showing the appearance of the head mounted display 8200.
  • a head-mounted display 8200 has a mounting section 8201, a lens 8202, a main body 8203, a display section 8204, a cable 8205, and the like.
  • a battery 8206 is built in the mounting portion 8201 .
  • a cable 8205 supplies power from a battery 8206 to the main body 8203 .
  • a main body 8203 includes a wireless receiver or the like, and can display received video information on a display portion 8204 .
  • the main body 8203 is equipped with a camera, and information on the movement of the user's eyeballs or eyelids can be used as input means.
  • the mounting section 8201 may be provided with a plurality of electrodes capable of detecting a current flowing along with the movement of the user's eyeballs at a position where it touches the user, and may have a function of recognizing the line of sight. Moreover, it may have a function of monitoring the user's pulse based on the current flowing through the electrode.
  • the mounting unit 8201 may have various sensors such as a temperature sensor, a pressure sensor, an acceleration sensor, etc., and has a function of displaying biological information of the user on the display unit 8204, In addition, a function of changing an image displayed on the display portion 8204 may be provided.
  • the display device of one embodiment of the present invention can be applied to the display portion 8204 .
  • FIG. 21C to 21E are diagrams showing the appearance of the head mounted display 8300.
  • FIG. A head mounted display 8300 includes a housing 8301 , a display portion 8302 , a band-shaped fixture 8304 , and a pair of lenses 8305 .
  • the user can visually recognize the display on the display unit 8302 through the lens 8305 .
  • the display portion 8302 it is preferable to arrange the display portion 8302 in a curved manner because the user can feel a high presence.
  • three-dimensional display or the like using parallax can be performed.
  • the configuration is not limited to the configuration in which one display portion 8302 is provided, and two display portions 8302 may be provided and one display portion may be arranged for one eye of the user.
  • the display device of one embodiment of the present invention can be applied to the display portion 8302 .
  • the display device of one embodiment of the present invention can also achieve extremely high definition. For example, even when the display is magnified using the lens 8305 as shown in FIG. 21E and viewed, the pixels are difficult for the user to view. In other words, the display portion 8302 can be used to allow the user to view highly realistic images.
  • FIG. 21F is a diagram showing the appearance of a goggle-type head-mounted display 8400.
  • the head mounted display 8400 has a pair of housings 8401, a mounting section 8402, and a cushioning member 8403.
  • a display portion 8404 and a lens 8405 are provided in the pair of housings 8401, respectively.
  • the user can visually recognize the display unit 8404 through the lens 8405.
  • the lens 8405 has a focus adjustment mechanism, and the focus adjustment mechanism can adjust the position of the lens 8405 according to the user's vision.
  • the display portion 8404 is preferably square or horizontally long rectangular. This makes it possible to enhance the sense of presence.
  • the mounting part 8402 preferably has plasticity and elasticity so that it can be adjusted according to the size of the user's face and does not slip off.
  • a part of the mounting portion 8402 preferably has a vibration mechanism that functions as a bone conduction earphone. As a result, you can enjoy video and audio without the need for separate audio equipment such as earphones and speakers.
  • the housing 8401 may have a function of outputting audio data by wireless communication.
  • the mounting part 8402 and the cushioning member 8403 are parts that come into contact with the user's face (forehead, cheeks, etc.). Since the cushioning member 8403 is in close contact with the user's face, it is possible to prevent light leakage and enhance the sense of immersion. It is preferable to use a soft material for the cushioning member 8403 so that the cushioning member 8403 comes into close contact with the user's face when the head mounted display 8400 is worn by the user. For example, materials such as rubber, silicone rubber, urethane, and sponge can be used.
  • a member that touches the user's skin is preferably detachable for easy cleaning or replacement.
  • the electronic device shown in FIGS. 22A to 22F includes a housing 9000, a display unit 9001, a speaker 9003, operation keys 9005 (including a power switch or an operation switch), connection terminals 9006, sensors 9007 (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, smell, or infrared rays , detection or measurement), a microphone 9008, and the like.
  • the electronic devices shown in FIGS. 22A to 22F have various functions. For example, a function to display various information (still images, moving images, text images, etc.) on the display unit, a touch panel function, a calendar, a function to display the date or time, a function to control processing by various software (programs), It can have a wireless communication function, a function of reading and processing programs or data recorded on a recording medium, and the like. Note that the functions of the electronic device are not limited to these, and can have various functions.
  • the electronic device may have a plurality of display units.
  • the electronic device is equipped with a camera, etc., and has the function of capturing still images or moving images and storing them in a recording medium (external or built into the camera), or the function of displaying the captured image on the display unit, etc. good.
  • the display device of one embodiment of the present invention can be applied to the display portion 9001 .
  • FIG. 22A is a perspective view showing a mobile information terminal 9101.
  • the mobile information terminal 9101 can be used as a smart phone, for example.
  • the portable information terminal 9101 may be provided with a speaker 9003, a connection terminal 9006, a sensor 9007, and the like.
  • the mobile information terminal 9101 can display text and image information on its multiple surfaces.
  • FIG. 22A shows an example in which three icons 9050 are displayed.
  • Information 9051 indicated by a dashed rectangle can also be displayed on another surface of the display portion 9001 . Examples of the information 9051 include notification of incoming e-mail, SNS, telephone, etc., title of e-mail, SNS, etc., sender name, date and time, remaining battery power, strength of antenna reception, and the like.
  • an icon 9050 or the like may be displayed at the position where the information 9051 is displayed.
  • FIG. 22B is a perspective view showing the mobile information terminal 9102.
  • the portable information terminal 9102 has a function of displaying information on three or more sides of the display portion 9001 .
  • information 9052, information 9053, and information 9054 are displayed on different surfaces.
  • the user can confirm the information 9053 displayed at a position where the mobile information terminal 9102 can be viewed from above the mobile information terminal 9102 while the mobile information terminal 9102 is stored in the chest pocket of the clothes.
  • the user can check the display without taking out the portable information terminal 9102 from the pocket, and can determine, for example, whether to receive a call.
  • FIG. 22C is a perspective view showing a wristwatch-type mobile information terminal 9200.
  • the mobile information terminal 9200 can be used as a smart watch (registered trademark), for example.
  • the display portion 9001 has a curved display surface, and display can be performed along the curved display surface.
  • Hands-free communication is also possible by allowing the mobile information terminal 9200 to communicate with, for example, a headset capable of wireless communication.
  • the portable information terminal 9200 can transmit data to and from another information terminal through the connection terminal 9006, and can be charged. Note that the charging operation may be performed by wireless power supply.
  • FIG. 22D to 22F are perspective views showing a foldable personal digital assistant 9201.
  • FIG. 22D is a perspective view of the portable information terminal 9201 in an unfolded state
  • FIG. 22F is a folded state
  • FIG. 22E is a perspective view of a state in the middle of changing from one of FIGS. 22D and 22F to the other.
  • the portable information terminal 9201 has excellent portability in the folded state, and has excellent display visibility due to a seamless wide display area in the unfolded state.
  • a display portion 9001 included in the portable information terminal 9201 is supported by three housings 9000 connected by hinges 9055 .
  • the display portion 9001 can be bent with a curvature radius of 0.1 mm or more and 150 mm or less.
  • This embodiment can be implemented by appropriately combining at least part of it with other embodiments described herein.
  • Example 1 In this example, a display panel of one embodiment of the present invention was manufactured. In this example, a display panel with a resolution of 3078 ppi was manufactured.
  • the display panel was manufactured based on the method exemplified in Embodiment 1 and Manufacturing Method Example 1.
  • FIG. Specifically, first, a substrate provided with a pixel circuit including a transistor, wiring, and the like and a pixel electrode formed on a single crystal silicon substrate was prepared. Subsequently, after sequentially forming a red EL layer, a green EL layer, and a blue EL layer, the sacrificial layer and protective layer on each EL layer were removed. Subsequently, an electron injection layer, a common electrode, and a protective layer were sequentially formed over the EL layer.
  • EL layer a layered structure of a hole injection layer, a hole transport layer, a light emitting layer, and an electron transport layer was formed.
  • An aluminum oxide film formed by ALD at a substrate temperature of 80° C. was used as the sacrificial layer, and an In—Ga—Zn oxide film formed by sputtering was used as the protective layer.
  • LiF was used for the electron injection layer, a mixed film of silver and magnesium was used for the common electrode, and an ITO film formed by a sputtering method was used for the protective layer on the common electrode.
  • FIG. 23A shows an optical microscope photograph of pixels of the manufactured display panel.
  • the pixel pitch is about 8.25 ⁇ m
  • the sub-pixel pitch is about 2.75 ⁇ m
  • the pixel aperture ratio (design value) is about 33.7% (the sub-pixel aperture ratio is about 11.75 ⁇ m). equivalent to 2% ⁇ 3).
  • FIG. 23B shows a cross-sectional STEM observation photograph of a pixel of the manufactured display panel.
  • the pixel shown in FIG. 23B is a green (G) sub-pixel.
  • An insulating layer 131 covers the edge of the pixel electrode 111G.
  • An EL layer 112G is provided over the pixel electrode 111G and the insulating layer 131 .
  • An electron injection layer, a common electrode 113, and a protective layer 121 are provided to cover the EL layer 112G.
  • a protective film 129 for analysis is provided on the protective layer 121 .
  • the taper angle of the EL layer 112G is approximately 83°, confirming that it has a nearly vertical shape.
  • Example 1 In this example, a display panel of one embodiment of the present invention was manufactured.
  • the display panel manufactured in this example has a square display portion with a diagonal size of 0.99 inches, an effective pixel count of 1920 ⁇ 1920, a resolution of 2731 ppi, a pixel pitch of 9.3 ⁇ m ⁇ 9.3 ⁇ m, and a pixel
  • the arrangement is an R, G, B stripe arrangement, the aperture ratio is 43% (design value), and the frame frequency is 90 Hz.
  • the display panel was fabricated by using a single-crystal silicon substrate as a substrate and stacking a single-crystal silicon transistor, a wiring layer, an oxide semiconductor transistor (OS transistor), and a light-emitting element in this order.
  • a light-emitting device was fabricated in the same manner as in Example 1, except that a tungsten film formed by a sputtering method was used as the second sacrificial layer (protective layer).
  • FIG. 24 shows a cross-sectional observation image of the manufactured display device.
  • the right side shows a cross section from the wiring layer to the light emitting element, and the left side shows an enlarged view of the OS transistor and its vicinity.
  • a single crystal silicon substrate and a single crystal silicon transistor formed on the substrate are provided below the wiring layer.
  • the OS transistor uses an In-Ga-Zn oxide film (IGZO) for the semiconductor layer.
  • FIG. 24 shows the top gate, back gate, source, drain, and capacitor of the OS transistor.
  • FIGS. 25A and 25B Display photographs of the manufactured display panel are shown in FIGS. 25A and 25B.
  • a color image with extremely high definition of 2731 ppi can be realized by a separate painting method that does not use a metal mask.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Optics & Photonics (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Geometry (AREA)
  • Electroluminescent Light Sources (AREA)
  • Devices For Indicating Variable Information By Combining Individual Elements (AREA)
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CN202280010483.6A CN116803210A (zh) 2021-01-28 2022-01-14 显示装置
US18/273,122 US20240090253A1 (en) 2021-01-28 2022-01-14 Display device
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US20240090253A1 (en) 2024-03-14

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