Light-emitting apparatus, display apparatus, photoelectric conversion apparatus, electronic device, illumination apparatus, moving body, and method for producing light-emitting apparatus

Abstract

Provided is a light-emitting apparatus comprising: a substrate on which a display region that is provided with a plurality of pixels and a peripheral region that is provided with a circuit for operating the plurality of pixels are disposed; and a first transistor which is disposed in the display region and a second transistor which is disposed in the peripheral region. The first transistor is provided with a first gate insulating film and a first channel region. In the first gate insulating film, the film thickness of a portion that covers an end of the first channel region in the channel width direction is greater than the film thickness of a portion that covers the center of the first channel region in the channel width direction. The second transistor is provided with a second gate insulating film and a second channel region. In the second gate insulating film, the film thickness of a portion that covers an end of the second channel region in the channel width direction is equal to or smaller than the film thickness of a portion that covers the center of the second channel region in the channel width direction.

Description

Light-emitting device, display device, photoelectric conversion device, electronic device, lighting device, mobile object, and method for manufacturing light-emitting device

[0001] The present invention relates to a light-emitting device, a display device, a photoelectric conversion device, an electronic device, a lighting device, a mobile object, and a method for manufacturing a light-emitting device.

[0002] In a light-emitting device including a self-luminous element using an organic electroluminescence (EL) element or the like, it is required to suppress display unevenness in the display area while increasing the speed of a drive circuit disposed in a peripheral area. To achieve both suppression of display unevenness and an increase in the speed of the drive circuit, it is important to suppress characteristic variations in the transistors disposed in the display area while improving the switching characteristics of the transistors disposed in the peripheral area. Patent Document 1 discloses a method of arranging element isolation regions to make the thickness of a gate insulating film covering the channel region of each transistor uniform across the entire display area.

[0003] Japanese Patent Application Laid-Open No. 2016-213436

[0004] As shown in Patent Document 1, consider the case where transistors in which the thickness of the gate insulating film is uniform between the center of the channel region and the edge of the channel region facing the element isolation region are used in both the display region and the peripheral region. In the transistor in the display region, which is driven at a high voltage, a strong electric field is applied between the gate electrode and the edge of the channel region, raising concerns about variations in transistor characteristics due to hump characteristics. On the other hand, in the transistor in the peripheral region, which is driven at a low voltage, the sub-channel at the edge of the channel region cannot be utilized, making it difficult to improve switching characteristics.

[0005] An object of the present invention is to provide a technique that is advantageous in achieving both suppression of variations in transistors arranged in the display region and improvement of the characteristics of transistors arranged in the peripheral region.

[0006] In view of the above problems, a light-emitting device according to an embodiment of the present invention is a light-emitting device having a substrate on which a display region having a plurality of pixels and a peripheral region having a circuit for operating the plurality of pixels are arranged, a first transistor arranged in the display region, and a second transistor arranged in the peripheral region, wherein the first transistor includes a first gate insulating film and a first channel region, and the first gate insulating film has a thickness of a portion covering an end portion in a channel width direction of the first channel region that is thicker than a portion covering a center portion in the channel width direction of the first channel region, and the second transistor includes a second gate insulating film and a second channel region, and the thickness of a portion covering an end portion in the channel width direction of the second channel region is equal to or less than a thickness of a portion covering the center portion in the channel width direction of the second channel region.

[0007] According to the present invention, it is possible to provide a technique that is advantageous in achieving both suppression of variations in transistors arranged in the display region and improvement of the characteristics of transistors arranged in the peripheral region.

[0008] Other features and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings, in which the same or similar elements are designated by the same reference numerals.

[0009] 1 is a diagram showing an example of the configuration of a light-emitting device of this embodiment. FIG. 2 is a diagram showing an example of the configuration of a pixel arranged in the light-emitting device of FIG. 1. FIG. 3 is a top view showing an example of a transistor arranged in the light-emitting device of FIG. 1. FIG. 4 is a cross-sectional view showing an example of the configuration of a transistor arranged in a display region of the light-emitting device of FIG. 1. FIG. 5 is a cross-sectional view showing an example of the configuration of a transistor arranged in a peripheral region of the light-emitting device of FIG. 1. FIG. 6 is a cross-sectional view showing an example of the configuration of a transistor arranged in a peripheral region of the light-emitting device of FIG. 1. FIG. 7 is a diagram for explaining a transistor arranged in the light-emitting device of FIG. 1. FIG. 8 is a diagram showing an example of a method for manufacturing a transistor arranged in the light-emitting device of FIG. 1. FIG. 9 is a diagram showing an example of a method for manufacturing a transistor arranged in the light-emitting device of FIG. 1. FIG. 10 is a diagram showing an example of a method for manufacturing a transistor arranged in the light-emitting device of FIG. 1. FIG. 11 is a diagram showing an example of a method for manufacturing a transistor arranged in the light-emitting device of FIG. 1. FIG. 12 is a diagram showing an example of a method for manufacturing a transistor arranged in the light-emitting device of FIG. 1. FIG. 13 is a diagram showing an example of a method for manufacturing a transistor arranged in the light-emitting device of FIG. 1. 1 is a cross-sectional view showing an example of the configuration of a pixel of the light-emitting device of the present embodiment. 2 is a cross-sectional view showing an example of the configuration of a pixel of the light-emitting device of the present embodiment. 3 is a view showing an example of an image forming device using the light-emitting device of the present embodiment. 4 is a view showing an example of an image forming device using the light-emitting device of the present embodiment. 5 is a view showing an example of an image forming device using the light-emitting device of the present embodiment. 6 is a view showing an example of a display device using the light-emitting device of the present embodiment. 7 is a view showing an example of a photoelectric conversion device using the light-emitting device of the present embodiment. 8 is a view showing an example of an electronic device using the light-emitting device of the present embodiment. 9 is a view showing an example of a display device using the light-emitting device of the present embodiment. 10 is a view showing an example of a display device using the light-emitting device of the present embodiment. 11 is a view showing an example of a lighting device using the light-emitting device of the present embodiment. 12 is a view showing an example of a moving object using the light-emitting device of the present embodiment. 13 is a view showing an example of a wearable device using the light-emitting device of the present embodiment. 14 is a view showing an example of a wearable device using the light-emitting device of the present embodiment.

[0010] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0011] A light-emitting device according to an embodiment of the present disclosure will be described with reference to FIGS. 1 to 7 . FIG. 1 is a diagram illustrating an example of the configuration of a light-emitting device 100 according to this embodiment. The light-emitting device 100 includes a substrate 101 on which a display region 102 including a plurality of pixels 104 and a peripheral region 103 including circuits for operating the plurality of pixels 104 are arranged. The display region 102 and the peripheral region 103 can be said to be formed on a single substrate 101. In the display region 102, a plurality of pixels are arranged two-dimensionally in a matrix. Each of the pixels 104 includes, for example, an organic light-emitting element (EL element, also referred to as an OLED). The peripheral region 103 includes circuits for driving (operating) each pixel 104. For example, a vertical scanning circuit 105, a signal output circuit 106, a control circuit 107, and the like are arranged in the peripheral region 103.

[0012] In the display area 102, scanning lines 108 are arranged for each pixel row along the row direction (horizontal direction in FIG. 1 ). Furthermore, in the display area 102, signal lines 109 are arranged for each pixel column along the column direction (vertical direction in FIG. 1 ). The control circuit 107 supplies a vertical scanning control signal 110 to the vertical scanning circuit 105 and a signal output signal 111 to the signal output circuit 106. The scanning lines 108 are connected to the output terminals of the corresponding rows of the vertical scanning circuit 105. Furthermore, the signal lines 109 are connected to the output terminals of the corresponding columns of the signal output circuit 106. The vertical scanning circuit 105 outputs write signals to each scanning line 108 in accordance with the vertical scanning control signal 110. The signal output circuit 106 takes in image data supplied from the control circuit 107 in accordance with the signal output signal 111. The signal output circuit 106 digital-to-analog converts the image data and outputs luminance signals corresponding to the values ​​of the image data to each signal line 109.

[0013] FIG. 2 is a diagram showing an example of the circuit configuration of a pixel 104 arranged in the display region 102 of the light-emitting device 100. As shown in FIG. 2, the pixel 104 may include a light-emitting element 200, a driving transistor 201, a light-emission control transistor 202, a writing transistor 203, and a reset transistor 204. The transistor connections shown in FIG. 2 are merely an example, and the P-type and N-type transistors may be different. The light-emitting element 200 may have an organic layer including a light-emitting layer between an anode and a cathode. In addition to the light-emitting layer, the organic layer may appropriately include one or more of a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, and a charge generation layer. The pixel 104 may also be provided with two capacitances 205 and 206. The capacitances 205 and 206 may be capacitance elements with a MOS structure or an MIM structure, or may be realized by parasitic capacitances parasitic on the driving transistor 201, the light-emission control transistor 202, the writing transistor 203, etc. The pixel 104 is supplied with a power supply potential 210 and a power supply potential 211 .

[0014] The drive transistor 201, the light-emission control transistor 202, the write transistor 203, and the reset transistor 204 may each be a MOSFET. Hereinafter, these four transistors may be referred to as pixel transistors. A control signal supplied from the vertical scanning circuit 105 to the pixel 104 is input to the gates of the light-emission control transistor 202, the write transistor 203, and the reset transistor 204 via three scanning lines 108a, 108b, and 108c, respectively. A signal line 109 is connected to one main terminal (the source in the configuration of FIG. 2 ) of the write transistor 203. When the write transistor 203 is turned on (conductive) in response to a signal supplied to the scanning line 108b, the voltage value of the signal line 109 is input to the gate of the drive transistor 201. The value of the current between the source and drain of the drive transistor 201 is determined according to the voltage value of this signal, thereby controlling the light-emission brightness of the light-emitting element 200. One main terminal (drain in the configuration of FIG. 2 ) of the drive transistor 201 is connected to one main terminal (anode in the configuration of FIG. 2 ) of the light-emitting element 200 and one main terminal (source in the configuration of FIG. 2 ) of the reset transistor 204. The light-emitting control transistor 202 is arranged between a power supply potential 210 and the drive transistor 201, and controls whether the light-emitting element 200 emits light or not in accordance with a signal supplied to the scanning line 108 a. When the reset transistor 204 is turned on in accordance with a signal supplied to the scanning line 108 c, the anode of the light-emitting element 200 is reset to a power supply potential 211. In the configuration shown in FIG. 2 , the same power supply potential 211 is supplied to the other main terminal (cathode in the configuration of FIG. 2 ) of the light-emitting element 200 and the other main terminal (drain in the configuration of FIG. 2 ) of the reset transistor 204. Therefore, when the reset transistor 204 is on, no current flows through the light-emitting element 200, and the light-emitting element 200 does not emit light. The potential settings of the power supply potential 210 and the power supply potential 211 can be determined appropriately depending on the conversion characteristics of the light emitting element 200 .

[0015] FIG. 3 is a top view showing an example of a transistor arranged in the light-emitting device 100 of this embodiment. A transistor 351 is arranged in the display region 102 formed on the substrate 101 using a single-crystal silicon substrate or the like. The transistor 351 is an example of the pixel transistor described above. The transistor 351 includes an activation region 301 (the activation region 301 includes a channel region 311 shown in FIG. 4A ) isolated by an isolation region 303, a gate electrode 302, and a gate insulating film (the gate insulating film 322 shown in FIG. 4A ) arranged between the gate electrode 302 and the channel region 311. By applying a voltage to the gate electrode 302, a channel is formed in the channel region between the source and drain. The length of the channel in the direction from the source to the drain is defined as the channel length, and the direction intersecting the channel length is defined as the channel width. A transistor 352 is arranged in the peripheral region 103 formed on the substrate 101. The transistor 352 includes an activation region 304 (the activation region 304 includes a channel region 314 shown in FIG. 5A ) isolated by an isolation region 306, a gate electrode 305, and a gate insulating film (gate insulating film 325 shown in FIG. 5A ) disposed between the gate electrode 305 and the channel region 314. The light-emitting device 100 includes a plurality of transistors 351 and 352 isolated by the isolation regions 303 and 306 in this manner. The transistor 351 disposed in the display region 102 and the transistor 352 disposed in the peripheral region 103 are provided within the same substrate 101. An impurity region well of N-type or P-type conductivity is formed in the activation regions 301 and 304, and the gate electrodes 302 and 305 are disposed on the activation regions 301 and 304 via gate insulating films 322 and 325 made of silicon oxide or the like. The gate electrodes 302 and 305 are formed of silicon (e.g., polysilicon) or the like. The element isolation regions 303 and 306 are formed using a dielectric material such as silicon oxide. In FIG. 3, the gate insulating film and the element isolation regions are formed integrally, but they may be formed separately. They may also be made of different materials. The element isolation regions 303 and 306 may have an STI structure from the viewpoint of miniaturization between transistors, etc.The STI structure is a structure in which a trench is provided on a semiconductor substrate to separate transistors, and a dielectric such as silicon oxide may be disposed in the trench, or the trench may be filled with a dielectric.

[0016] 4A is a cross-sectional view showing a configuration example of the channel region 311 of the transistor 351 arranged in the display region 102 between A-A' shown in FIG. 3. As shown in FIG. 4A, the gate insulating film 322 of the transistor 351 is formed so that the portion covering the end of the channel region 311 in the channel width direction has a bird's beak shape 401. It can also be said that the element isolation region 303 is formed so that the end of the gate insulating film 322 in the gate width direction has the bird's beak shape 401. An example of forming the element isolation region 303 will be described later.

[0017] Generally, the ends of a MOS transistor's channel region in the channel width direction are more susceptible to electric field concentration between the gate electrode and the substrate and a decrease in the impurity concentration in the active region than the center of the channel region in the channel width direction. Therefore, when the MOS transistor is driven, a sub-channel is formed, which tends to result in a hump characteristic. In the light-emitting device 100, the pixel transistors are driven at a higher voltage than the transistors arranged in the logic circuit in the peripheral region 103. Therefore, electric field concentration tends to result in a hump characteristic, which can cause variations in brightness between pixels 104 due to variations in the swing characteristics of the pixel transistors, resulting in display unevenness.

[0018] Therefore, as shown in FIG. 4A , the transistor 351 disposed in the display region 102 includes a gate insulating film 322 having a bird's beak shape 401 continuing from the element isolation region 303. As a result, the thickness D of the gate insulating film 322 of the transistor 351, which covers the ends of the channel region 311 in the channel width direction, is thicker than the thickness C of the gate insulating film 322 of the transistor 351, which covers the center of the channel region 311 in the channel width direction. By applying the transistor 351 having the gate insulating film 322 as shown in FIG. 4A as the pixel transistor, it is possible to alleviate electric field concentration at the ends of the channel region 311 in the channel width direction. This makes it possible to suppress variations in swing characteristics due to hump characteristics, suppress variations in luminance, and as a result, suppress display unevenness in the light-emitting device 100.

[0019] Here, the center of the channel region 311 in the channel width direction may refer to, for example, one of the central regions obtained by dividing the channel region 311 into three equal regions in the channel width direction, or may refer to two of the central regions obtained by dividing the channel region 311 into four equal regions in the channel width direction.

[0020] FIG. 4B is a diagram showing a modified example of the transistor 351 shown in FIG. 4A . In the structure shown in FIG. 4B , a divot is formed in the bird's beak-shaped portion of the gate insulating film 322 that extends from the isolation region 303 and covers the channel width direction end. Depending on the manufacturing process, a divot-shaped depression may occur at the boundary between the activation region 301 and the isolation region 303, even in the isolation region 303 that has the bird's beak shape 401. Even in this case, it is sufficient that the film thickness D of the portion of the gate insulating film 322 that covers the channel width direction end of the channel region 311 is thicker than the film thickness C of the portion that covers the center of the channel region 311 in the channel width direction. This suppresses electric field concentration at the channel width direction end of the channel region of the transistor 351. As a result, the formation of a subchannel is suppressed, and the hump characteristics are suppressed, thereby suppressing the display unevenness of the light-emitting device 100 as described above.

[0021] 5A is a cross-sectional view showing a configuration example of the channel region 314 of the transistor 352 arranged in the peripheral region 103 between lines B-B' shown in FIG. 3. As shown in FIG. 5A, the gate insulating film 325 of the transistor 352 is formed so that the portion covering the end of the channel region 314 in the channel width direction has a divot shape 501. The divot shape may also be referred to as a recess. It can also be said that the element isolation region 306 is formed so that the end of the gate insulating film 325 in the gate width direction has the divot shape 501. An example of forming the element isolation region 306 will be described later.

[0022] Transistors used in the logic circuit of the control circuit 107 arranged in the peripheral region 103 are generally driven at a lower voltage than pixel transistors. In other words, a higher voltage is applied to the transistor 351 (pixel transistor) than to the transistor 352 (e.g., a transistor constituting a logic circuit). The transistor 352 used in the logic circuit is required to have switching characteristics, so it is necessary to improve the Ion characteristics for higher speed rather than reducing the hump characteristics. Here, the Ion characteristics refer to the driving force of the transistor (on-current in the saturated region).

[0023] Therefore, as shown in FIG. 5A , the transistor 352 disposed in the peripheral region 103 includes a gate insulating film 325 having a divot shape extending from the element isolation region 303. As a result, the thickness D of the gate insulating film 325 of the transistor 352, which covers the ends of the channel region 314 in the channel width direction, is thinner than the thickness C of the portion covering the center of the channel region 314 in the channel width direction. The thickness D need only be equal to or less than the thickness C. By applying the transistor 352 having the gate insulating film 325 shown in FIG. 5A as the transistor disposed in the peripheral region 103, an electric field can be concentrated at the ends of the channel region 314 in the channel width direction, forming a sub-channel. This improves the Ion characteristics of the transistor 352 and enables the speed of circuits disposed in the peripheral region 103 of the light-emitting device 100 to be increased.

[0024] 5B is a diagram showing a modified example of the transistor 352 shown in FIG. 5A. In the structure shown in FIG. 5B, the surface of the element isolation region 306 is lower than the surface of the channel region 314. By making the surface of the element isolation region 306 lower than the surface of the channel region 314, the film thickness of the portion of the gate insulating film 325 covering the end of the channel region 314 in the channel width direction becomes thinner. This allows the electric field to be concentrated at the end of the channel region 314 in the channel width direction, forming a sub-channel. This improves the Ion characteristics of the transistor 352 and enables the speed of circuits arranged in the peripheral region 103 of the light-emitting device 100 to be increased.

[0025] FIG. 6 shows the relationship between the thickness of the gate insulating film of a transistor in the light-emitting device 100, between the portion covering the center of the channel region in the channel width direction and the portion covering the end of the channel region in the channel width direction. Embodiment 1 in FIG. 6 illustrates this relationship. That is, in the gate insulating film 322 of the transistor 351 arranged in the display region 102, the thickness D1 of the portion covering the end of the channel region 311 in the channel width direction is thicker than the thickness C1 of the portion covering the center of the channel region 311 in the channel width direction. On the other hand, in the gate insulating film 325 of the transistor 352 arranged in the peripheral region 103, the thickness D2 of the portion covering the end of the channel region 314 in the channel width direction is equal to or less than the thickness C2 of the portion covering the center of the channel region 314 in the channel width direction. This configuration makes it possible to both suppress display unevenness by suppressing variations in the transistors 351 arranged in the display region 102 of the light-emitting device 100 and increase speed by improving the characteristics of the transistors 352 arranged in the peripheral region 103.

[0026] The thickness C1 of the gate insulating film 322 of the transistor 351, which covers the center of the channel region 311 in the channel width direction, and the thickness C2 of the gate insulating film 325 of the transistor 352, which covers the center of the channel region 314 in the channel width direction, may be the same. That is, in the configuration shown in FIG. 6 , C1 may be equal to C2. Furthermore, for example, as described above, a higher voltage may be applied to the transistor 351 than to the transistor 352. Therefore, the thicknesses of the gate insulating films 322 and 325 of the transistors 351 and 352, which cover the center of the channel region 311 and 314 in the channel width direction, may be different. More specifically, the thickness C1 of the gate insulating film 322 of the transistor 351, which covers the center of the channel region 311 in the channel width direction, may be thicker than the thickness C2 of the gate insulating film 325 of the transistor 352, which covers the center of the channel region 314 in the channel width direction (C1>C2). The thicknesses of the gate insulating films 322 and 325 may be set as appropriate depending on the voltages applied to the transistors 351 and 352 .

[0027] Next, a second embodiment of FIG. 6 will be described. In addition to the transistor 352, which is required to have higher switching characteristics than voltage resistance, such as the logic circuit described above, the peripheral region 103 may also include transistors that require high voltage resistance to supply current corresponding to the voltage of a luminance signal to the pixels 104. For example, the signal output circuit 106 may include an analog circuit that handles analog signals for supplying luminance signals to the pixels 104. Transistors included in such analog circuits are required to suppress hump characteristics and variations in swing characteristics rather than high switching characteristics (Ion characteristics). Therefore, among the transistors included in the peripheral region 103 that constitute the analog circuit, the thickness D2' of the gate insulating film covering the end portions of the channel region in the channel width direction may be thicker than the thickness C2' of the gate insulating film covering the center of the channel region in the channel width direction, as in the transistor 351 described above.

[0028] Furthermore, a higher voltage may be applied to the transistors constituting the analog circuit arranged in the peripheral region 103 than to the transistors 352 constituting the logic circuit. Therefore, the thickness C2' of the gate insulating film of the transistor constituting the analog circuit, which covers the center of the channel region in the channel width direction, may be thicker than the thickness C2 of the gate insulating film 325 of the transistor 352 constituting the logic circuit, which covers the center of the channel region 314 in the channel width direction (C2'>C2).

[0029] 6 , the thickness C1 of a portion of the gate insulating film 322 of the transistor 351 arranged in the display region 102 that covers the center in the channel width direction of the channel region 311 and the thickness C2' of a portion of the gate insulating film of the transistor constituting the analog circuit that covers the center in the channel width direction of the channel region may be the same. Also, for example, the thickness C1 of the portion of the gate insulating film 322 of the transistor 351 arranged in the display region 102 that covers the center in the channel width direction of the channel region 311 may be thicker than the thickness C2' of the portion of the gate insulating film of the transistor constituting the analog circuit that covers the center in the channel width direction of the channel region (C1≧C2').

[0030] In the transistors arranged in the peripheral region 103, the structure of the gate insulating film is changed according to the applied voltage. The thickness of the gate insulating film is also changed. As a result, in addition to the effect of the first embodiment shown in FIG. 6 , the hump characteristics of the transistors used in the analog circuits arranged in the peripheral region 103 are suppressed, stabilizing the operating point. In other words, it is possible to increase the accuracy of the analog circuits arranged in the peripheral region 103. As a result, for example, the variation in the luminance signal from the analog circuits arranged in the peripheral region 103 is suppressed. In other words, in addition to the above-mentioned effect, it is possible to further improve the display quality in the display region 102.

[0031] Next, a third embodiment will be described with reference to FIG. 6 . In the display region 102, the drive transistor 201 is required to have a suppressed hump characteristic in order to control the light emission brightness of the light emitting element 200. That is, the transistor 351 is disposed as a transistor that functions as the drive transistor 201. On the other hand, for example, if the Ion characteristic of the light emission control transistor 202 is improved, the switching characteristic of the light emission control transistor 202 is improved, and it becomes possible to make the switching characteristic of the light emitting element 200 between emitting and not emitting light a steep characteristic.

[0032] 2 arranged in the pixel 104 has the configuration of the above-described transistor 351. On the other hand, the light-emission control transistor 202, the write transistor 203, and the reset transistor 204 may have the configuration of the above-described transistor 352. That is, the film thickness of the portions of the gate insulating films of the light-emission control transistor 202, the write transistor 203, and the reset transistor 204 that cover the ends of the channel region in the channel width direction may be equal to or smaller than the film thickness of the portions that cover the center of the channel region in the channel width direction. In this case, the film thickness of the portions of the gate insulating film of the drive transistor 201 that cover the center of the channel region in the channel width direction may be the same as the film thickness of the portions of the gate insulating films of the light-emission control transistor 202, the write transistor 203, and the reset transistor 204 that cover the center of the channel region in the channel width direction. Furthermore, for example, the film thickness of the portion of the gate insulating film of the driving transistor 201 that covers the center of the channel region in the channel width direction may be equal to or greater than the film thickness of the portion of the gate insulating film of the light-emitting control transistor 202, the write transistor 203, and the reset transistor 204 that covers the center of the channel region in the channel width direction (C1≧C1′).

[0033] The configuration of embodiment 3 in Fig. 6 makes it possible to improve the switching characteristics of the light-emitting control transistor 202, the write transistor 203, and the reset transistor 204. All of the three pixel transistors, the light-emitting control transistor 202, the write transistor 203, and the reset transistor 204, may have the configuration of transistor 352, or any one or more of them may have the configuration of transistor 352. Furthermore, the light-emitting device 100 may be realized by combining the configuration of embodiment 2 and the configuration of embodiment 3 shown in Fig. 6.

[0034] 7A to 7I will now be used to describe an example of a manufacturing method for the light emitting device 100 of this embodiment. First, as shown in Fig. 7A, silicon oxide 602 is formed on a silicon substrate 601, and then a silicon film 603 is formed on the silicon oxide 602. The silicon film 603 can be, for example, a polysilicon film.

[0035] Next, as shown in FIG. 7B , the silicon film 603 in the peripheral region 103 is removed by dry etching or the like using a resist mask. In FIG. 7B , the silicon film 603 is removed from the entire peripheral region 103. However, this is not limiting. When realizing the configuration of embodiment 2 shown in FIG. 6 described above, the silicon film 603 in the region of the peripheral region 103 where the logic circuit is formed (where the transistor 352 is formed) is removed. Similarly, when realizing the configuration of embodiment 3 described above, the silicon film 603 in the display region 102 other than the region where the drive transistor 201 is formed is removed. The steps shown in FIGS. 7A to 7I are example steps for realizing the configuration of embodiment 1 shown in FIG. 6 .

[0036] After patterning the silicon film 603, silicon nitride 604 is formed, as shown in Fig. 7C. In the display area 102, the silicon nitride 604 is formed on the patterned silicon film 603. In the peripheral area 103, the silicon nitride 604 is formed on the silicon oxide 602.

[0037] Next, as shown in FIG. 7D , trenches 622 and 623 for isolating the transistors disposed in the display region 102 and the peripheral region 103 are formed using a resist mask and dry etching or the like. The process of forming the trenches 622 and 623 may be performed by dividing the resist mask patterning process into two steps, so that the trenches 622 and 623 are formed separately in the display region 102 and the peripheral region 103. For example, the trench 622 in the display region 102 may be formed first, and then the trench 623 in the peripheral region 103 may be formed, or vice versa. For example, the trenches 622 and 623 may be formed separately depending on the voltages applied to the respective transistors. Furthermore, when implementing the configurations of Embodiments 2 and 3 shown in FIG. 6 , the trenches formed in the display region 102 and the peripheral region 103 may also be formed in two or more steps depending on, for example, the voltages applied to the transistors.

[0038] 7E, after trenches 622 and 623 are formed, silicon oxide 605 is formed on the surfaces of trenches 622 and 623 by using a thermal oxidation method or the like. At this time, since silicon film 603 is formed under silicon nitride 604 in display region 102, the side surfaces of silicon film 603 are oxidized by the oxidation process, and trench corners with bird's beak shapes 606 are formed.

[0039] 7F , the trenches 622 and 623 are filled with an insulator 607 such as silicon oxide using a high-density plasma chemical vapor deposition (CVD) method or the like. Furthermore, the insulator 607 is planarized using a chemical mechanical polishing (CMP) method or the like. Although not shown, before filling the insulator 607 and planarizing it using the CMP method, an etching process may be performed to remove the step of the silicon oxide between the active region and the isolation region.

[0040] After planarizing the insulator 607, as shown in FIG. 7G , the silicon nitride 604 and silicon film 603 are removed using wet etching or the like, and the height of the insulator 607 from the surface of the silicon substrate 601 is adjusted to form an STI structure for the element isolation region. Then, impurities are implanted into the silicon substrate 601 as appropriate to form an N-type or P-type conductive well. Next, the silicon oxide 602 is removed using wet etching or the like. At this time, the silicon substrate 601 is exposed in a portion that will become a center 608 of the channel region of the transistor in the display region 102. Meanwhile, silicon oxide remains in a portion that will become an end 609 of the channel region in the channel width direction due to the bird's beak shape formed during oxidation of the surfaces (sidewalls) of the trenches 622 and 623. Furthermore, the silicon substrate 601 is exposed in a portion that will become a center 610 of the channel region of the transistor in the peripheral region 103. On the other hand, in the portion that becomes the end 611 in the channel width direction of the channel region, the oxide silicon is isotropically etched by wet etching, so that a divot-shaped depression is formed at the corner of the insulator 607 of the STI structure, rather than a bird's beak shape.

[0041] 7H , a silicon oxide film 612 serving as a gate insulating film is formed by, for example, thermal oxidation. At this time, the silicon oxide film may be formed by in situ steam generation (ISSG) instead of thermal oxidation. After the gate insulating film is formed, a portion of the gate insulating film in the display region 102 that covers an end 613 of the channel region in the channel width direction is formed in a shape corresponding to the bird's beak shape of the underlying insulator 607. Meanwhile, a portion of the gate insulating film in the peripheral region 103 that covers an end 614 of the channel region in the channel width direction is formed in a shape corresponding to the divot shape of the underlying insulator 607.

[0042] In order to make the thickness of the gate insulating film different between the display region 102 and the peripheral region 103, after forming the silicon oxide 612, the silicon oxide 612 in the peripheral region 103 (or the display region 102) is removed by wet etching using a resist mask or the like. Next, a process flow may be used in which, for example, a thermal oxidation method is used to form silicon oxide in the peripheral region 103 (or the display region 102) having a thickness different from that of the silicon oxide in the display region 102 (or the peripheral region 103).

[0043] After the gate insulating film is formed, as shown in Fig. 7I, a gate electrode 615 of the transistor is formed by forming and patterning, for example, a polysilicon film using a low-pressure CVD method. By using the above process, the thickness of the gate insulating film covering the edges of the channel region in the channel width direction is thicker than that of the center of the channel region in the display region 102. On the other hand, the thickness of the gate insulating film covering the edges of the channel region in the channel width direction of the transistor in the peripheral region 103 is equal to or less than the thickness of the gate insulating film covering the center.

[0044] As described above, the light-emitting device 100 of this embodiment can simultaneously suppress variations in the transistors arranged in the display region 102 and improve the characteristics of the transistors arranged in the peripheral region 103. This suppresses display unevenness caused by variations in luminance in the display region 102, and enables the circuitry arranged in the peripheral region 103 to operate at a high speed.

[0045] 8A and 8B to 16A and 16B, application examples in which the light-emitting device 100 of this embodiment is applied to an image forming device, a display device, a photoelectric conversion device, an electronic device, a lighting device, a mobile object, and a wearable device will be described. The description will be made assuming that a light-emitting element, such as an organic EL element using an organic light-emitting material, is disposed in the pixel 104 disposed in the light-emitting device 100. First, details of each component disposed in the pixel of the light-emitting device 100 will be shown, and then application examples will be described.

[0046] Structure of Organic Light-Emitting Element The organic light-emitting element is provided by forming an insulating layer, a first electrode, an organic compound layer, and a second electrode on a substrate. A protective layer, a color filter, a microlens, etc. may be provided on the cathode. When a color filter is provided, a planarizing layer may be provided between the protective layer and the color filter. The planarizing layer may be made of an acrylic resin or the like. The same applies when a planarizing layer is provided between the color filter and the microlens.

[0047] Substrate Examples of the substrate include quartz, glass, silicon wafer, resin, and metal. Furthermore, the substrate may be provided with switching elements such as transistors and wiring patterns, and an insulating layer may be provided thereon. When a silicon wafer is used as the substrate, the active layer, source region, and drain region of the transistor are formed within the substrate. Furthermore, it is suitable because it allows transistors to be densely arranged. The insulating layer may be made of any material as long as it allows contact holes to be formed so that a wiring pattern can be formed between the first electrode and the substrate, and insulation from unconnected wiring patterns is ensured. For example, the insulating layer may be made of a resin such as polyimide, silicon oxide, silicon nitride, or the like.

[0048] Electrodes A pair of electrodes can be used as the electrodes. The pair of electrodes may be an anode and a cathode. When an electric field is applied in the direction in which the organic light-emitting element emits light, the electrode with a higher potential is the anode, and the other is the cathode. It can also be said that the electrode that supplies holes to the light-emitting layer is the anode, and the electrode that supplies electrons is the cathode.

[0049] The anode may be made of a material with a high work function. For example, a metal such as gold, platinum, silver, copper, nickel, palladium, cobalt, selenium, vanadium, or tungsten, a mixture containing these metals, or an alloy of these metals, or a metal oxide such as tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), or zinc indium oxide, may be used. Alternatively, a conductive polymer such as polyaniline, polypyrrole, or polythiophene may be used as the anode.

[0050] These electrode materials may be used alone or in combination of two or more. The anode may be composed of one layer or multiple layers.

[0051] When the electrode is used as a reflective electrode, for example, chromium, aluminum, silver, titanium, tungsten, molybdenum, or an alloy thereof, or a laminate of these, can be used. The above materials can also function as a reflective film without functioning as an electrode. Furthermore, when a transparent electrode is used as the electrode, a transparent conductive oxide layer such as indium tin oxide (ITO) or indium zinc oxide can be used, but is not limited to these. Photolithography technology can be used to form the electrode.

[0052] On the other hand, a material with a low work function may be selected as the cathode material. Examples include alkali metals such as lithium, alkaline earth metals such as calcium, and metals such as aluminum, titanium, manganese, silver, lead, and chromium, as well as mixtures containing these metals. Alternatively, alloys combining these metals may be used. For example, magnesium-silver, aluminum-lithium, aluminum-magnesium, silver-copper, and zinc-silver may be used. Metal oxides such as indium tin oxide (ITO) may also be used. These electrode materials may be used alone or in combination of two or more. The cathode may have a single-layer structure or a multilayer structure. Silver may be used as the cathode, and a silver alloy may be used to reduce silver aggregation. The alloy ratio is not important as long as silver aggregation is reduced. For example, the silver:other metal ratio may be 1:1, 3:1, or the like.

[0053] The cathode may be a top-emission element using an oxide conductive layer such as ITO, or a bottom-emission element using a reflective electrode such as aluminum (Al), and is not particularly limited. The method for forming the cathode is not particularly limited, but using a DC or AC sputtering method or the like can provide good coverage of the formed film and reduce the resistance of the cathode.

[0054] Pixel Separation Layer The pixel separation layer may be formed of silicon oxides such as silicon nitride (SiN), silicon oxynitride (SiON), or silicon oxide (SiO) formed using a chemical vapor deposition (CVD) method. To increase the in-plane resistance of the organic compound layer, the thickness of the organic compound layer, particularly the hole transport layer, may be thinned on the sidewalls of the pixel separation layer. Specifically, the thickness of the organic compound layer on the sidewalls can be thinned by increasing the taper angle of the sidewalls of the pixel separation layer or the thickness of the pixel separation layer, thereby increasing vignetting during deposition.

[0055] On the other hand, the sidewall taper angle and film thickness of the pixel separation layer can be adjusted to an extent that voids are not formed in the protective layer formed thereon. By preventing voids from being formed in the protective layer, the occurrence of defects in the protective layer can be reduced. Since the occurrence of defects in the protective layer is reduced, deterioration of reliability such as the occurrence of dark spots and poor conduction of the second electrode can be reduced.

[0056] According to this embodiment, charge leakage to adjacent pixels can be effectively suppressed even if the taper angle of the sidewall of the pixel separation layer is not steep. As a result of this study, it was found that charge leakage can be sufficiently reduced if the taper angle is in the range of 60 degrees or more and 90 degrees or less. The thickness of the pixel separation layer may be 10 nm or more and 150 nm or less. Similar effects can also be achieved even if the pixel electrode is composed only of a pixel electrode without a pixel separation layer. However, in this case, short circuits in organic light-emitting elements can be reduced by making the thickness of the pixel electrode half or less of the organic layer, or by making the edge of the pixel electrode forward tapered by less than 60 degrees.

[0057] Furthermore, even when the first electrode is a cathode and the second electrode is an anode, a wide color gamut and low voltage driving are possible by forming an electron transporting material and a charge transporting layer, and also by forming a light-emitting layer on the charge transporting layer.

[0058] Organic Compound Layer The organic compound layer may be formed as a single layer or as multiple layers. When multiple layers are included, they may be called hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, hole blocking layer, electron transport layer, electron injection layer, etc., depending on their functions. The organic compound layer is mainly composed of organic compounds but may also contain inorganic atoms or inorganic compounds. The organic compound layer may contain, for example, copper, lithium, magnesium, aluminum, iridium, platinum, molybdenum, zinc, etc. The organic compound layer may be disposed between the first electrode and the second electrode, or may be disposed in contact with the first electrode and the second electrode.

[0059] In the case where a plurality of light-emitting layers are included, a charge generation portion may be provided between the first light-emitting layer and the second light-emitting layer. The charge generation portion may include an organic compound having a lowest unoccupied molecular orbital energy (LUMO) of −5.0 eV or less. The same applies to the case where a charge generation portion is provided between the second light-emitting layer and the third light-emitting layer.

[0060] Protective Layer A protective layer may be provided on the cathode. For example, by adhering glass with a moisture absorbent to the cathode, the intrusion of moisture and other contaminants into the organic compound layer can be reduced, thereby reducing the occurrence of display defects. In another embodiment, a passivation layer such as silicon nitride may be provided on the cathode to reduce the intrusion of moisture and other contaminants into the organic compound layer. For example, after forming the cathode, the cathode may be transferred to another chamber without breaking the vacuum, and silicon nitride with a thickness of 2 μm may be formed by CVD to serve as a protective layer. After forming the protective layer by CVD, a protective layer may be formed by atomic layer deposition (ALD). The material of the protective layer formed by ALD is not limited, and may be silicon nitride, silicon oxide, aluminum oxide, or the like. Silicon nitride may be further formed by CVD on the protective layer formed by ALD. The protective layer formed by ALD may have a smaller thickness than the protective layer formed by CVD. Specifically, the thickness of the protective layer formed by the ALD method may be 50% or less, or even 10% or less, of the thickness of the protective layer formed by the CVD method.

[0061] Color Filter A color filter may be provided on the protective layer. For example, a color filter taking into consideration the size of the organic light-emitting element may be provided on another substrate, and the substrate on which the color filter is formed may be bonded to the substrate on which the organic light-emitting element is provided. Alternatively, for example, a color filter may be patterned on the above-mentioned protective layer using photolithography technology. The color filter may be made of a polymer.

[0062] Planarization Layer A planarization layer may be disposed between the color filter and the protective layer. The planarization layer is provided for the purpose of reducing the unevenness of the layers below the planarization layer. It may also be called a material resin layer without limiting the purpose. The planarization layer may be composed of an organic compound, and may be a low molecular weight or a high molecular weight compound. In consideration of reducing the unevenness, a high molecular weight organic compound may be used for the planarization layer.

[0063] The planarization layers may be provided above and below the color filter. In this case, the constituent materials of the planarization layers may be the same or different. Specific examples of the material for the planarization layer include polyvinyl carbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin, and urea resin.

[0064] Microlenses The organic light-emitting device may have an optical component such as a microlens on its light-emitting side. The microlens may be made of acrylic resin, epoxy resin, or the like. The purpose of the microlens may be to increase the amount of light extracted from the organic light-emitting device or to control the direction of the extracted light. The microlens may have a hemispherical shape. When the microlens has a hemispherical shape, among the tangents to the hemisphere, there is a tangent that is parallel to the insulating layer, and the point of contact between this tangent and the hemisphere is the vertex of the microlens. The vertex of the microlens can be determined in the same way in any cross-sectional view. In other words, among the tangents to the semicircle of the microlens in the cross-sectional view, there is a tangent that is parallel to the insulating layer, and the point of contact between this tangent and the semicircle is the vertex of the microlens.

[0065] It is also possible to define the midpoint of a microlens. In the cross section of the microlens, a line segment is imagined from the point where an arc shape ends to the point where another arc shape ends, and the midpoint of this line segment can be called the midpoint of the microlens. The cross section for determining the vertex and midpoint may be a cross section perpendicular to the insulating layer.

[0066] The microlens has a first surface having a convex portion and a second surface opposite the first surface. The second surface can be disposed closer to the functional layer (light-emitting layer) than the first surface. To achieve this configuration, it is necessary to form the microlens on the light-emitting device. If the functional layer is an organic layer, high-temperature processes can be avoided in the microlens manufacturing process. Furthermore, when the second surface is disposed closer to the functional layer than the first surface, the glass transition temperatures of the organic compounds constituting the organic layer may all be 100°C or higher, and are preferably, for example, 130°C or higher.

[0067] Counter substrate A counter substrate may be disposed on the planarization layer. The counter substrate is called a counter substrate because it is provided at a position corresponding to the aforementioned substrate. The constituent material of the counter substrate may be the same as that of the aforementioned substrate. When the aforementioned substrate is the first substrate, the counter substrate may be the second substrate.

[0068] Organic Layer The organic compound layers (hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, hole blocking layer, electron transport layer, electron injection layer, etc.) constituting the organic light-emitting device according to an embodiment of the present disclosure may be formed by the method shown below.

[0069] The organic compound layer constituting the organic light-emitting element according to the embodiment of the present disclosure can be formed by a dry process such as vacuum deposition, ionization deposition, sputtering, plasma, etc. Alternatively, a wet process can be used in which a compound is dissolved in an appropriate solvent and a layer is formed by a known coating method (e.g., spin coating, dipping, casting, LB method, inkjet method, etc.).

[0070] Here, when a layer is formed by a vacuum deposition method or a solution coating method, crystallization is unlikely to occur and the layer has excellent stability over time. When a film is formed by a coating method, the film can be formed by combining it with an appropriate binder resin.

[0071] Examples of the binder resin include, but are not limited to, polyvinyl carbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin, and urea resin.

[0072] These binder resins may be used singly or in combination as homopolymers or copolymers, and may further contain known additives such as plasticizers, antioxidants, and ultraviolet absorbers, if necessary.

[0073] Pixel Circuit The light-emitting device may have a pixel circuit connected to the light-emitting element. The pixel circuit may be an active matrix type that controls the emission of the first light-emitting element and the second light-emitting element independently. The active matrix type circuit may be voltage-programmed or current-programmed. The drive circuit has a pixel circuit for each pixel. The pixel circuit may have a light-emitting element, a transistor that controls the emission brightness of the light-emitting element, a transistor that controls the emission timing, a capacitor that holds the gate voltage of the transistor that controls the emission brightness, and a transistor for connecting to GND without going through the light-emitting element.

[0074] The light-emitting device has a display region and a peripheral region arranged around the display region. The display region has pixel circuits, and the peripheral region has a display control circuit. The mobility of a transistor constituting the pixel circuit may be lower than the mobility of a transistor constituting the display control circuit.

[0075] The slope of the current-voltage characteristics of the transistors that make up the pixel circuit may be smaller than the slope of the current-voltage characteristics of the transistors that make up the display control circuit. The slope of the current-voltage characteristics can be measured by the so-called Vg-Ig characteristics.

[0076] The transistors that make up the pixel circuit are transistors connected to the light-emitting elements, such as the first light-emitting element.

[0077] Pixels An organic light emitting device includes a plurality of pixels, each of which includes sub-pixels that emit different colors, for example, each of which may emit RGB light.

[0078] A pixel has an area that emits light, also called a pixel aperture. The pixel aperture may be 15 μm or less, or 5 μm or more. More specifically, it may be 11 μm, 9.5 μm, 7.4 μm, 6.4 μm, etc.

[0079] The spacing between the subpixels may be 10 μm or less, and specifically may be 8 μm, 7.4 μm, or 6.4 μm.

[0080] The pixels may be arranged in a known manner in a plan view. For example, they may be in a stripe arrangement, a delta arrangement, a pentile arrangement, or a Bayer arrangement. The shape of the subpixels in a plan view may be any known shape. For example, they may be rectangular, quadrilaterals such as diamonds, or hexagons. Of course, a shape that is close to a rectangle, rather than an exact shape, is included in the rectangle. The shape of the subpixels and the pixel arrangement may be used in combination.

[0081] The organic light-emitting device according to the embodiment of the present disclosure can be used as a component of a display device or a lighting device. Other applications include an exposure light source for an electrophotographic image forming device, a backlight for a liquid crystal display device, and a light-emitting device having a white light source and a color filter.

[0082] The display device may be an image information processing device that has an image input unit that inputs image information from an area CCD, a linear CCD, a memory card, etc., has an information processing unit that processes the input information, and displays the input image on the display unit.

[0083] The display unit of the imaging device or inkjet printer may have a touch panel function. The driving method of this touch panel function may be an infrared method, a capacitance method, a resistive film method, or an electromagnetic induction method, and is not particularly limited. The display device may also be used in the display unit of a multifunction printer.

[0084] Next, further explanation will be provided with reference to the drawings. Fig. 8A shows an example of a pixel 104 arranged in the display region 102 of the light-emitting device 100. The pixel includes sub-pixels 810. The sub-pixels are divided into 810R, 810G, and 810B based on their light emission. The emitted light colors may be distinguished by the wavelength of light emitted from the light-emitting layer, or the light emitted from the sub-pixels may be selectively transmitted or color-converted using a color filter or the like. Each sub-pixel includes a reflective electrode 802 serving as a first electrode on an interlayer insulating layer 801, an insulating layer 803 covering the edge of the reflective electrode 802, an organic compound layer 804 covering the first electrode and the insulating layer, a transparent electrode 805 serving as a second electrode, a protective layer 806, and a color filter 807.

[0085] A transistor and a capacitor may be disposed below or inside the interlayer insulating layer 801. The transistor and the first electrode may be electrically connected via a contact hole (not shown) or the like.

[0086] The insulating layer 803 may also be called a bank or a pixel separation film. The insulating layer 803 covers the edges of the first electrodes and is disposed to surround the first electrodes. The portions of the first electrodes not covered by the insulating layer 803 are in contact with the organic compound layer 804 and become light-emitting regions.

[0087] The organic compound layer 804 includes a hole injection layer 841 , a hole transport layer 842 , a first light-emitting layer 843 , a second light-emitting layer 844 , and an electron transport layer 845 .

[0088] The second electrode may be a transparent electrode, a reflective electrode, or a semi-transparent electrode.

[0089] The protective layer 806 reduces the penetration of moisture into the organic compound layer. Although the protective layer is illustrated as a single layer, it may be a multi-layer structure. Each layer may include an inorganic compound layer and an organic compound layer.

[0090] The color filters 807 are divided into 807R, 807G, and 807B depending on their colors. The color filters may be formed on a planarization film (not shown). A resin protective layer (not shown) may be disposed on the color filters. The color filters may be formed on a protective layer 806. The color filters may be provided on an opposing substrate such as a glass substrate and then bonded thereto.

[0091] The display device 800 in FIG. 8B (corresponding to the light-emitting device 100 described above) includes an organic light-emitting element 826 and a TFT 818 as an example of a transistor. A substrate 811 made of glass, silicon, or the like is provided with an insulating layer 812 thereon. An active element such as a TFT 818 is disposed on the insulating layer, along with a gate electrode 813, a gate insulating film 814, and a semiconductor layer 815 of the active element. The TFT 818 also includes a semiconductor layer 815, a drain electrode 816, and a source electrode 817. An insulating film 819 is provided above the TFT 818. An anode 821 constituting the organic light-emitting element 826 and the source electrode 817 are connected via a contact hole 820 provided in the insulating film.

[0092] The electrical connection method between the electrodes (anode, cathode) included in the organic light-emitting element 826 and the electrodes (source electrode, drain electrode) included in the TFT is not limited to the mode shown in Fig. 8B. In other words, it is sufficient that either the anode or the cathode is electrically connected to either the TFT source electrode or the drain electrode. TFT stands for thin film transistor.

[0093] 8B shows the organic compound layer as a single layer, the organic compound layer 822 may be a multi-layer structure. A first protective layer 824 and a second protective layer 825 are provided on the cathode 823 to reduce deterioration of the organic light-emitting element.

[0094] Although the display device 800 of FIG. 8B uses transistors as switching elements, other switching elements may be used instead.

[0095] Furthermore, the transistors used in the display device 800 of Figure 8B are not limited to transistors using single-crystal silicon wafers, but may also be thin-film transistors having an active layer on an insulating surface of a substrate. Examples of active layers include single-crystal silicon, amorphous silicon, microcrystalline silicon, and other non-single-crystal silicon, and non-single-crystal oxide semiconductors such as indium zinc oxide and indium gallium zinc oxide. Thin-film transistors are also called TFT elements.

[0096] The transistors included in the display device 800 of Figure 8B may be formed within a substrate such as a silicon substrate. Here, "formed within a substrate" means that the transistors are fabricated by processing the substrate itself, such as a silicon substrate. In other words, having a transistor within a substrate can be seen as the substrate and the transistor being integrally formed.

[0097] The light emission luminance of the organic light-emitting element according to this embodiment is controlled by a TFT, which is an example of a switching element. By providing multiple organic light-emitting elements on a surface, an image can be displayed based on the respective light emission luminances. Here, the switching element according to this embodiment is not limited to a TFT, but may also be a transistor formed from low-temperature polysilicon or an active matrix driver formed on a substrate such as a silicon substrate. "On the substrate" can also be referred to as "inside the substrate." Whether to provide a transistor in the substrate or to use a TFT is selected depending on the size of the display unit. For example, if the size is about 0.5 inches, the organic light-emitting element may be provided on a silicon substrate.

[0098] 9A to 9C are schematic diagrams illustrating an example of an image forming apparatus using the light emitting device 100 of this embodiment. The image forming apparatus 926 shown in Fig. 9A includes a photoconductor 927, an exposure light source 928, a developing unit 931, a charging unit 930, a transfer unit 932, a transport unit 933 (a transport roller in the configuration of Fig. 9A), and a fixing unit 935. The light emitting device 100 described above can be used as the exposure light source 928 of the image forming apparatus 926.

[0099] Light 929 is emitted from an exposure light source 928, and an electrostatic latent image is formed on the surface of the photoconductor 927. The light-emitting device 100 can be applied to this exposure light source 928. The developing unit 931 contains toner or the like as a developer and can function as a developing device that applies the developer to the exposed photoconductor 927. The charging unit 930 charges the photoconductor 927. The transfer unit 932 transfers the developed image to a recording medium 934. The transport unit 933 transports the recording medium 934. The recording medium 934 can be, for example, paper or film. The fixing unit 935 fixes the image formed on the recording medium.

[0100] 9B and 9C are schematic diagrams showing an exposure light source 928 in which a plurality of light-emitting sections 936 are arranged along the longitudinal direction of a long substrate. The light-emitting device 100 can be applied to these light-emitting sections 936. In other words, a plurality of pixels are arranged along the longitudinal direction of the substrate. A direction 937 is parallel to the axis of the photosensitive member 927. This column direction is the same as the axial direction of the photosensitive member 927 when it rotates. This direction 937 can also be called the long axis direction of the photosensitive member 927.

[0101] FIG. 9B shows a configuration in which the light-emitting units 936 are arranged along the longitudinal axis of the photoconductor 927. FIG. 9C shows a modified example of the arrangement of the light-emitting units 936 shown in FIG. 9B, in which the light-emitting units 936 are arranged alternately in the column direction in the first and second columns. The light-emitting units 936 are arranged at different positions in the row direction in the first and second columns. In the first column, multiple light-emitting units 936 are arranged at intervals, and in the second column, light-emitting units 936 are arranged at positions corresponding to the gaps between the light-emitting units 936 in the first column. Multiple light-emitting units 936 are also arranged at intervals in the row direction. The arrangement of the light-emitting units 936 shown in FIG. 9C can be described as, for example, a grid-like arrangement, a houndstooth arrangement, or a checkerboard pattern.

[0102] FIG. 10 is a schematic diagram illustrating an example of a display device using the light-emitting device 100 of this embodiment. The display device 1000 may include a touch panel 1003, a display panel 1005, a frame 1006, a circuit board 1007, and a battery 1008 between an upper cover 1001 and a lower cover 1009. The touch panel 1003 and the display panel 1005 are connected to flexible printed circuits FPCs 1002 and 1004. An active element such as a transistor is disposed on the circuit board 1007. The battery 1008 may not be disposed if the display device 1000 is not a portable device, and even if it is a portable device, it does not need to be disposed in this position. The light-emitting device 100 can be applied to the display panel 1005. Light-emitting elements disposed in the light-emitting device 100 that functions as the display panel 1005 are connected to active elements such as transistors disposed on the circuit board 1007 and operate.

[0103] The display device 1000 shown in Fig. 10 may be used as a display unit of a photoelectric conversion device (which may also be called an imaging device) that has an optical unit with multiple lenses and an imaging element that receives light that has passed through the optical unit and photoelectrically converts it into an electrical signal. The photoelectric conversion device may have a display unit that displays information acquired by the imaging element. The display unit may be a display unit exposed to the outside of the photoelectric conversion device or a display unit located within a viewfinder. The photoelectric conversion device may be a digital camera or a digital video camera.

[0104] FIG. 11 is a schematic diagram illustrating an example of a photoelectric conversion device using the light-emitting device 100 of this embodiment. The photoelectric conversion device 1100 may include a viewfinder 1101, a rear display 1102, an operation unit 1103, and a housing 1104. The photoelectric conversion device 1100 may also be called an imaging device. The light-emitting device 100 of this embodiment can be applied to the viewfinder 1101 or the rear display 1102, which are display units. In this case, the light-emitting device 100 may display not only an image to be captured, but also environmental information, imaging instructions, and the like. The environmental information may include the intensity of external light, the direction of external light, the moving speed of the subject, the possibility that the subject will be blocked by an obstruction, and the like.

[0105] Since the timing suitable for capturing an image is often very short, it is better to display information as soon as possible. Therefore, a light-emitting device 100 in which pixels including light-emitting elements using an organic light-emitting material such as an organic EL element are arranged may be used in a viewfinder 1101 or a rear display 1102. This is because organic light-emitting materials have a fast response speed. A light-emitting device 100 using an organic light-emitting material is more suitable than a liquid crystal display device for these devices, which require a high display speed.

[0106] The photoelectric conversion device 1100 has an optical section (not shown). The optical section has multiple lenses, and forms an image on a photoelectric conversion element (not shown) housed in a housing 1104 that receives light that has passed through the optical section. The focus of the multiple lenses can be adjusted by adjusting their relative positions. This operation can also be performed automatically.

[0107] The light emitting device 100 may be applied to a display unit of an electronic device. In this case, the light emitting device 100 may have both a display function and an operation function. Examples of the portable terminal include a mobile phone such as a smartphone, a tablet, and a head-mounted display.

[0108] FIG. 12 is a schematic diagram showing an example of an electronic device using the light-emitting device 100 of this embodiment. The electronic device 1200 has a display unit 1201, an operation unit 1202, and a housing 1203. The housing 1203 may have a circuit, a printed circuit board having the circuit, a battery, and a communication unit. The operation unit 1202 may be a button or a touch panel type reaction unit. The operation unit 1202 may be a biometric recognition unit that recognizes a fingerprint to perform unlocking, etc. A portable device having a communication unit can also be called a communication device. The light-emitting device 100 of this embodiment can be applied to the display unit 1201.

[0109] 13A and 13B are schematic diagrams illustrating an example of a display device using the light-emitting device 100 of this embodiment. FIG. 13A illustrates a display device such as a television monitor or a PC monitor. The display device 1300 has a frame 1301 and a display unit 1302. The light-emitting device 100 of this embodiment can be applied to the display unit 1302. The display device 1300 may have a base 1303 that supports the frame 1301 and the display unit 1302. The base 1303 is not limited to the form shown in FIG. 13A . For example, the lower side of the frame 1301 may also serve as the base 1303. The frame 1301 and the display unit 1302 may be curved. The radius of curvature may be 5000 mm or more and 6000 mm or less.

[0110] FIG. 13B is a schematic diagram illustrating another example of a display device using the light-emitting device 100 of this embodiment. The display device 1310 of FIG. 13B is configured to be bendable, and is a so-called foldable display device. The display device 1310 has a first display unit 1311, a second display unit 1312, a housing 1313, and a bending point 1314. The light-emitting device 100 of this embodiment can be applied to the first display unit 1311 and the second display unit 1312. The first display unit 1311 and the second display unit 1312 may be a single display unit without any joints. The first display unit 1311 and the second display unit 1312 can be separated by the bending point. The first display unit 1311 and the second display unit 1312 may display different images, or the first display unit and the second display unit may display a single image.

[0111] FIG. 14 is a schematic diagram illustrating an example of an illumination device using the light-emitting device 100 of this embodiment. The illumination device 1400 may include a housing 1401, a light source 1402, a circuit board 1403, an optical film 1404, and a light diffusion unit 1405. The light-emitting device 100 of this embodiment can be applied to the light source 1402. The optical film 1404 may be a filter that improves the color rendering of the light source. The light diffusion unit 1405 can effectively diffuse light from the light source, such as for illumination, and deliver the light over a wide area. If necessary, a cover may be provided on the outermost part. The illumination device 1400 may include both the optical film 1404 and the light diffusion unit 1405, or only one of them.

[0112] The lighting device 1400 is, for example, a device that illuminates a room. The lighting device 1400 may emit white, daylight white, or any other color from blue to red. It may have a dimming circuit that adjusts the light intensity. The lighting device 1400 may have a power supply circuit connected to the light-emitting device 100 that functions as the light source 1402. The power supply circuit is a circuit that converts AC voltage to DC voltage. White has a color temperature of 4200 K, and daylight white has a color temperature of 5000 K. The lighting device 1400 may also have a color filter. The lighting device 1400 may also have a heat sink. The heat sink dissipates heat from within the device to the outside, and examples of the heat sink include metal with a high specific heat, liquid silicon, etc.

[0113] FIG. 15 is a schematic diagram of an automobile having a tail lamp, which is an example of a vehicle lamp using the light-emitting device 100 of this embodiment. The automobile 1500 may have a tail lamp 1501, and may be configured to turn on the tail lamp 1501 when braking or the like is performed. The light-emitting device 100 of this embodiment may be used as a headlamp as a vehicle lamp. An automobile is an example of a mobile body, and the mobile body may be a ship, a drone, an aircraft, a railroad vehicle, an industrial robot, or the like. The mobile body may have a body and a lamp provided thereon. The lamp may indicate the current location of the body.

[0114] The light emitting device 100 of this embodiment can be applied to a tail lamp 1501. The tail lamp 1501 may have a protective member that protects the light emitting device 100 that functions as the tail lamp 1501. The protective member may be made of any material as long as it has a certain degree of strength and is transparent, but may be made of polycarbonate or the like. The protective member may also be made by mixing a furandicarboxylic acid derivative, an acrylonitrile derivative, or the like with polycarbonate.

[0115] The automobile 1500 may have a body 1503 and a window 1502 attached thereto. The window may be a window for checking the front and rear of the automobile, or may be a transparent display such as a head-up display. The light-emitting device 100 of this embodiment may be used in the transparent display. In this case, the constituent materials of the electrodes and the like of the light-emitting device 100 are made of transparent materials.

[0116] 16A and 16B , a further application example of the light emitting device 100 of this embodiment will be described. The light emitting device 100 can be applied to systems that can be worn as a wearable device, such as smart glasses, a head-mounted display (HMD), or smart contact lenses. An image capturing and displaying device used in such an application example includes an image capturing device capable of photoelectrically converting visible light and a light emitting device capable of emitting visible light.

[0117] 16A illustrates glasses 1600 (smart glasses) according to one application example. An imaging device 1602 such as a CMOS sensor or a SPAD is provided on the front side of a lens 1601 of the glasses 1600. Furthermore, the light-emitting device 100 of this embodiment is provided on the back side of the lens 1601.

[0118] The glasses 1600 further include a control device 1603. The control device 1603 functions as a power source that supplies power to the image capture device 1602 and the light emitting device 100 according to each embodiment. The control device 1603 also controls the operations of the image capture device 1602 and the light emitting device 100. The lens 1601 is formed with an optical system for focusing light onto the image capture device 1602.

[0119] FIG. 16B illustrates glasses 1610 (smart glasses) according to one application example. The glasses 1610 include a control device 1612, which is equipped with an imaging device corresponding to the imaging device 1602 and a light-emitting device 100. A lens 1611 includes an optical system for projecting light emitted from the imaging device in the control device 1612 and the light-emitting device 100, and an image is projected onto the lens 1611. The control device 1612 functions as a power source for supplying power to the imaging device and the light-emitting device 100 and controls the operation of the imaging device and the light-emitting device 100. The control device 1612 may also include a gaze detection unit that detects the gaze of the wearer. Infrared light may be used for gaze detection. The infrared light-emitting unit emits infrared light toward the eyeball of a user gazing at a displayed image. An imaging unit having a light-receiving element detects the emitted infrared light reflected from the eyeball, thereby obtaining an image of the eyeball. By providing a reduction means for reducing the amount of light from the infrared light emitting section to the display section in a plan view, degradation of image quality is reduced.

[0120] The gaze of the user relative to the displayed image is detected from an image of the eyeball obtained by capturing infrared light. Any known method can be used for gaze detection using the image of the eyeball. As an example, a gaze detection method based on the Purkinje image formed by reflection of irradiated light on the cornea can be used.

[0121] More specifically, gaze detection processing is performed based on the pupil-corneal reflex method, which calculates a gaze vector representing the direction (rotation angle) of the eyeball based on the pupil image and Purkinje image included in the captured image of the eyeball, thereby detecting the user's gaze.

[0122] The light emitting device 100 according to the embodiment of the present disclosure may include an imaging device having a light receiving element, and may control the display image based on user line of sight information from the imaging device.

[0123] Specifically, the light-emitting device 100 determines a first field of view area where the user gazes and a second field of view area other than the first field of view area based on the line-of-sight information. The first field of view area and the second field of view area may be determined by a control device of the light-emitting device 100, or may be determined by an external control device and received. In the display area of ​​the light-emitting device 100, the display resolution of the first field of view area may be controlled to be higher than the display resolution of the second field of view area. In other words, the resolution of the second field of view area may be lower than that of the first field of view area.

[0124] The display area includes a first display area and a second display area different from the first display area, and a high-priority area is determined from the first display area and the second display area based on line-of-sight information. The first display area and the second display area may be determined by a control device of the light-emitting device 100, or may be determined by an external control device and received. The resolution of the high-priority area may be controlled to be higher than the resolution of areas other than the high-priority area. In other words, the resolution of an area with a relatively low priority may be lowered.

[0125] Note that AI may be used to determine the first field of view area and areas with high priority. The AI ​​may be a model configured to estimate the angle of gaze and the distance to an object in the line of sight from the image of the eyeball, using as training data an image of the eyeball and the actual direction in which the eyeball in the image was looking. The AI ​​program may be included in the light-emitting device 100, the imaging device, or an external device. If included in an external device, it is transmitted to the light-emitting device 100 via communication.

[0126] When display control is performed based on visual recognition detection, the smart glasses can be applied to smart glasses that further include an imaging device for capturing images of the outside world. The smart glasses can display captured outside information in real time.

[0127] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention.

[0128] This application claims priority based on Japanese Patent Application No. 2024-100745, filed June 21, 2024, the entire contents of which are incorporated herein by reference.

Claims

1. A light-emitting device having a substrate on which a display region having a plurality of pixels and a peripheral region having a circuit for operating the plurality of pixels are arranged, and a first transistor arranged in the display region and a second transistor arranged in the peripheral region, wherein the first transistor includes a first gate insulating film and a first channel region, and the first gate insulating film has a thickness that is greater at portions covering the ends of the first channel region in the channel width direction than at portions covering the center of the first channel region in the channel width direction, and the second transistor includes a second gate insulating film and a second channel region, and the second gate insulating film has a thickness that is less than or equal to the thickness of a portion covering the ends of the second channel region in the channel width direction.

2. The light emitting device according to claim 1, wherein a higher voltage is applied to the first transistor than to the second transistor.

3. The light-emitting device according to claim 1 or 2, wherein the substrate includes a single-crystal silicon substrate.

4. The light emitting device according to any one of claims 1 to 3, characterized in that an element isolation region is provided between the first transistor and another transistor, and the element isolation region has an STI structure.

5. The light emitting device according to any one of claims 1 to 4, wherein the second transistor constitutes a logic circuit among the circuits arranged in the peripheral region.

6. A light-emitting device described in any one of claims 1 to 5, characterized in that the film thickness of the portion of the first gate insulating film that covers the center of the channel width direction of the first channel region is thicker than the film thickness of the portion of the second gate insulating film that covers the center of the channel width direction of the second channel region.

7. A light-emitting device according to any one of claims 1 to 6, further comprising a third transistor arranged in the peripheral region, the third transistor comprising a third gate insulating film and a third channel region, and wherein the thickness of a portion of the third gate insulating film covering the center of the third channel region in the channel width direction is thicker than the thickness of a portion of the second gate insulating film covering the center of the second channel region in the channel width direction.

8. The light-emitting device described in claim 7, characterized in that the thickness of the third gate insulating film at the portion covering the end portion of the third channel region in the channel width direction is thicker than the thickness of the portion covering the center portion of the third channel region in the channel width direction.

9. A light-emitting device according to any one of claims 1 to 6, further comprising a third transistor arranged in the peripheral region, wherein the third transistor comprises a third gate insulating film and a third channel region, and wherein the thickness of the third gate insulating film at a portion covering an end of the third channel region in the channel width direction is thicker than the thickness of the portion covering the center of the third channel region in the channel width direction.

10. The light emitting device according to any one of claims 7 to 9, wherein a higher voltage is applied to the third transistor than to the second transistor.

11. The light emitting device according to any one of claims 7 to 10, wherein the third transistor constitutes an analog circuit among the circuits arranged in the peripheral region.

12. A light-emitting device according to any one of claims 1 to 11, further comprising a fourth transistor arranged in the display region, wherein the fourth transistor comprises a fourth gate insulating film and a fourth channel region, and the thickness of the fourth gate insulating film at a portion covering an end of the fourth channel region in the channel width direction is equal to or less than the thickness of a portion covering the center of the fourth channel region in the channel width direction.

13. A light-emitting device according to any one of claims 1 to 12, characterized in that each of the plurality of pixels includes a light-emitting element and a drive transistor that controls the light-emitting brightness of the light-emitting element in accordance with a signal input to a gate, and the first transistor is a transistor that functions as the drive transistor.

14. The light-emitting device described in claim 12, characterized in that each of the plurality of pixels includes a light-emitting element, a drive transistor that controls the light-emitting brightness of the light-emitting element in accordance with a signal input to a gate, and a light-emitting control transistor that controls whether the light-emitting element emits light, and the first transistor functions as the drive transistor, and the fourth transistor functions as the light-emitting control transistor.

15. A light-emitting device comprising: a substrate on which a display region having a plurality of pixels and a peripheral region having a circuit for operating the plurality of pixels are arranged; a first transistor arranged in the display region and a second transistor arranged in the peripheral region, wherein the first transistor includes a first gate insulating film and a first channel region, and a portion of the first gate insulating film covering an end of the first channel region in the channel width direction has a bird's beak shape; and the second transistor includes a second gate insulating film and a second channel region, and a portion of the second gate insulating film covering an end of the second channel region in the channel width direction has a divot shape.

16. A display device comprising a light-emitting device according to any one of claims 1 to 15 and an active element connected to said light-emitting device.

17. A photoelectric conversion device comprising an optical unit having a plurality of lenses, an image sensor that receives light that has passed through the optical unit, and a display unit that displays an image, wherein the display unit displays an image captured by the image sensor, and the device comprises a light-emitting device according to any one of claims 1 to 15.

18. An electronic device comprising: a housing in which a display unit is provided; and a communication unit provided in the housing for communicating with the outside, wherein the display unit has a light-emitting device according to any one of claims 1 to 15.

19. A lighting device having a light source and at least one of a light diffusing section and an optical film, wherein the light source has a light emitting device according to any one of claims 1 to 15.

20. A mobile body having a body and a lighting fixture provided on the body, wherein the lighting fixture has a light-emitting device according to any one of claims 1 to 15.

21. A method for manufacturing a light-emitting device including a display region having a plurality of pixels and a peripheral region having a circuit for operating the plurality of pixels, the device including a first transistor arranged in the display region and a second transistor arranged in the peripheral region, the method comprising: a first step of forming silicon oxide on a silicon substrate; a second step of forming a silicon film on the silicon oxide after the first step; a third step of removing the silicon film from a region of the silicon film where the second transistor will be formed after the second step; a fourth step of forming silicon nitride after the third step; a fifth step of forming trenches for element isolation of the first transistor and the second transistor after the fourth step; and a sixth step of performing oxidation treatment to form silicon oxide on the surface of the trench after the fifth step.

22. The manufacturing method according to claim 21, wherein in the fifth step, a trench for isolating the first transistor and a trench for isolating the second transistor are formed separately.

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