JP2007179030A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-performance and high-reliability display device with a high aperture ratio, including light-emitting elements, and a manufacturing method thereof, and a technique for manufacturing such a display device, at a low cost with high productivity. <P>SOLUTION: A compensating circuit, a light-emitting element, a switch, and a transistor are included, in which one terminal of the switch is electrically connected to the compensating circuit, a gate of the transistor is electrically connected to the compensating circuit, one of a source and a drain of the transistor is electrically connected to a first electrode of the light-emitting element, the other of the source and the drain of the transistor is maintained at a fixed potential, and a second electrode of the light-emitting element and the other terminal of the switch are electrically connected to the same wire. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a display device using a light emitting element.

In recent years, an electroluminescence display device in which thin film transistors (hereinafter also referred to as “TFTs”) are integrated on a substrate has been developed. In each of these display devices, a thin film transistor is formed on a substrate by using a thin film forming technique, and a light emitting element (hereinafter referred to as “EL”) is used as a display element on various circuits formed by the thin film transistor. .) Element) is formed to function as a display device.

In a pixel of a display device using a light emitting element, a current flowing through the light emitting element varies depending on variations in electrical characteristics such as a threshold voltage of a TFT constituting the pixel, and luminance of the light emitting element varies. There is. A configuration is disclosed in which such variations in the threshold voltage of TFTs are corrected using capacitive means (see, for example, Patent Document 1).
US Pat. No. 6,229,506

However, with the above pixel configuration, it is necessary to form a plurality of wirings in the pixel, so that the aperture ratio may decrease in the pixel. Further, the wirings are densely installed, and the wiring configuration is complicated and precise. Therefore, if the process is difficult and complicated, many defects may occur, resulting in a decrease in yield.

In view of such circumstances, an object of the present invention is to provide a high-performance and high-reliability display device having a light-emitting element and a manufacturing method thereof. Another object of the present invention is to provide a technique capable of manufacturing a display device with low cost and high productivity.

The present invention can be used for a display device having a display function, and the display device using the present invention includes an organic substance that emits light called electroluminescence (hereinafter also referred to as “EL”), or a mixture of an organic substance and an inorganic substance. There is a display device in which a light-emitting element and a TFT in which a layer including is interposed between electrodes is connected.

Note that in this specification, a semiconductor device refers to a device that can function by utilizing semiconductor characteristics. Therefore, it can be said that a display device including a transistor or the like is also a semiconductor device.

One display device of the present invention includes a correction circuit, a light-emitting element, a switch, and a transistor. One terminal of the switch is electrically connected to the correction circuit, and the gate of the transistor is electrically connected to the correction circuit. One of the source and the drain of the transistor is electrically connected to the first electrode of the light-emitting element, the other of the source and the drain of the transistor is kept at a constant potential, and the second electrode and the switch of the light-emitting element The other terminal is electrically connected to the same wiring.

One display device of the present invention includes a correction circuit, a light-emitting element, a first switch, a second switch, a transistor, and a control circuit, and one terminal of the control circuit has a constant potential. One terminal of the first switch is electrically connected to the correction circuit, one terminal of the second switch is electrically connected to the correction circuit, and the other terminal of the second switch is the first terminal. The transistor gate is electrically connected to the correction circuit, and one of the source and drain of the transistor is electrically connected to the first electrode of the light-emitting element, and the source and drain of the transistor The other is electrically connected to the other terminal of the control circuit, and the second electrode of the light emitting element and the other terminal of the first switch are electrically connected to the same second wiring.

One display device of the present invention includes a light-emitting element, a first switch, a second switch, a transistor, a first capacitor element, and a second capacitor element. One terminal is electrically connected to the first electrode of the second capacitor, and the second electrode of the second capacitor is the one terminal of the second switch and the first of the first capacitor. The second electrode of the first capacitor is kept at a constant potential, the gate of the transistor is electrically connected to the first electrode of the second capacitor, and the transistor One of a source and a drain is electrically connected to the first electrode of the light-emitting element, and the other of the source and the drain of the transistor is electrically connected to the other terminal of the second switch and is kept at a constant potential; The second electrode of the light emitting element and the other terminal of the first switch are It is electrically connected to the Flip wiring.

One embodiment of the display device of the present invention includes a light-emitting element, a first switch, a second switch, a third switch, a fourth switch, a transistor, a first capacitor, One terminal of the fourth switch is kept at a constant potential, and one terminal of the first switch is electrically connected to the first electrode of the second capacitor element, The second electrode of the second capacitive element is electrically connected to one terminal of the second switch and the first electrode of the first capacitive element, and the second electrode of the first capacitive element is constant The one terminal of the third switch is electrically connected to the second electrode of the second capacitor, and the other terminal of the third switch is electrically connected to the first wiring. The gate of the transistor is electrically connected to the first electrode of the second capacitor, the source of the transistor, and One of the rain is electrically connected to the first electrode of the light-emitting element, and the other of the source and the drain of the transistor is electrically connected to the other terminal of the second switch and the other terminal of the fourth switch. The second electrode of the light emitting element and the other terminal of the first switch are electrically connected to the same second wiring.

When the present invention is used, the number of wirings in a pixel can be simplified, so that an aperture ratio can be improved and a manufacturing process is also simplified. Therefore, such a highly reliable display device can be manufactured with high yield. Further, according to the present invention, a display device can be manufactured with low cost and high productivity.

Embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it is easily understood by those skilled in the art that modes and details can be variously changed without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the description of the embodiments below. Note that in structures of the present invention described below, the same portions or portions having similar functions are denoted by the same reference numerals in different drawings, and description thereof is not repeated.

(Embodiment 1)
An embodiment of the present invention will be described with reference to FIG. The pixel illustrated in FIG. 1A includes a transistor 101, switches 102 and 103, a light-emitting element 104, a control circuit 105a, a control circuit 105b, and a correction circuit 106. In addition, this invention is not limited to the structure of FIG. 1, It does not necessarily need to have all the said structures.

An example in which the transistor 152 and the transistor 153 are used as the switch 102 and the switch 103 in FIG. 1A is illustrated in FIG. The transistor 101 is a transistor that controls light emission of the light emitting element, the transistor 153 is a transistor that controls input of a video signal to the pixel, the wiring 107 is a wiring that transmits a video signal, and the wiring 108 is a wiring that is kept at a constant potential. The wiring 109 is a wiring maintained at a constant potential. Further, the potential of the wiring 108 and the potential of the wiring 109 are different from each other and have a potential difference.

The conductivity types of the transistors 101, 152, and 153 may be either N-channel or P-channel.

A gate of the transistor 153 is connected to the wiring 110, one of a source and a drain is connected to the wiring 107, and the other of the source and the drain is connected to the correction circuit 106. The gate of the transistor 152 is connected to the fifth wiring 111, one of the source and the drain is connected to the correction circuit 106, and the other of the source and the drain is connected to the wiring 109.

The gate of the transistor 101 is connected to the correction circuit 106, one of the source and the drain is connected to the control circuit 105a, and the other of the source and the drain is connected to the control circuit 105b. The control circuit 105 b is connected to the first electrode of the light emitting element 104. The control circuit 105 a is connected to the wiring 108, and the second electrode of the light emitting element 104 is connected to the wiring 109. In the present invention, in FIG. 1B, the transistor 152 and the light-emitting element 104 are connected to a common wiring 109.

As shown in FIG. 26A, one terminal of the switch 102 may be connected to the control circuit 105 b instead of the correction circuit 106, and the other terminal may be connected to the wiring 109. 26B, one of the source and the drain of the transistor 152 may be connected to the control circuit 105b instead of the correction circuit 106, and the other of the source and the drain may be connected to the wiring 109.

27A, one terminal of the switch 102 may be connected to the control circuit 105a instead of the correction circuit 106, and the other terminal may be connected to the wiring 109. In FIG. 27B, one of the source and the drain of the transistor 152 may be connected to the control circuit 105a instead of the correction circuit 106, and the other of the source and the drain may be connected to the wiring 109.

28A and 28B, the control circuit 105a is not provided, the correction circuit 106 is connected to the wiring 108, and one of the source and the drain of the transistor 101 may be connected to the correction circuit 106. . As described above, the place where the switch 102 (transistor 152) is provided in the pixel of the present invention is not limited to that in FIG. 1 and can be appropriately provided as shown in FIGS. As described above, the pixel of the present invention does not necessarily include both the control circuit 105a and the control circuit 105b, and may have a configuration including only the control circuit 105a or only one of the control circuits 105b.

FIG. 2 shows an example of a pixel to which the present invention is applied, in which the correction circuit 106 and the control circuits 105a and 105b of FIG. 2A includes a transistor 101, a switch 102, a switch 103, a light-emitting element 104, a switch 121, a switch 122, a capacitor 123, and a capacitor 124. The pixel illustrated in FIG. In the pixel in FIG. 2A, the switch 122, the capacitor 123, and the capacitor 124 correspond to the correction circuit 106 in FIG. 1A. In the pixel in FIG. This corresponds to the control circuit 105a of (A). 2B, the transistor 162, the capacitor 123, and the capacitor 124 correspond to the correction circuit 106 in FIG. 1B. In the pixel in FIG. 2B, the transistor 161 in FIG. This corresponds to the control circuit 105a of (B).

An example in which the transistor 152, the transistor 153, the transistor 161, and the transistor 162 are used as the switch 102, the switch 103, the switch 121, and the switch 122 in FIG. 2A is illustrated in FIG.

The gate of the transistor 153 is connected to the wiring 110, one of the source and the drain is connected to the wiring 107, and the other of the source and the drain is connected to the first electrode of the capacitor 124 and one of the source and the drain of the transistor 162. Has been. The gate of the transistor 162 is connected to the wiring 130, one of the source and the drain is connected to the first electrode of the capacitor 123, and the other of the source and the drain is one of the source and the drain of the transistor 161 and the source and the drain of the transistor 101. Connected to one of the. The gate of the transistor 161 is connected to the wiring 131, and the other of the source and the drain is connected to the wiring 108.

A second electrode of the capacitor 123 is connected to the wiring 108. A second electrode of the capacitor 124 is connected to one of a source and a drain of the transistor 152 and a gate of the transistor 101. The gate of the transistor 152 is connected to the wiring 111, and the other of the source and the drain is connected to the wiring 109. The other of the source and the drain of the transistor 101 is connected to the first electrode of the light-emitting element 104. A second electrode of the light emitting element 104 is connected to the wiring 109. In FIG. 2B, the present invention is characterized in that the transistor 152 and the light-emitting element 104 are connected to a common wiring 109.

First, the switches 121, 122, and 102 are turned on, and the switch 103 is turned off. Then, current flows from the wiring 108 to the wiring 109 through the switch 121, the switch 122, the second capacitor element 124, and the switch 102, and the second capacitor element 124 is charged. When the voltage held in the second capacitor element 124 exceeds the threshold voltage of the transistor 101, the transistor 101 is turned on. When the transistor 101 is turned on, current flows from the wiring 108 to the wiring 109 through the switch 121, the transistor 101, and the light-emitting element 104.

Next, the switches 122 and 102 are turned on, and the switches 121 and 103 are turned off. The charge held in the second capacitor element 124 is discharged, and a current flows through the switch 122, the transistor 101, the light-emitting element 104, the switch 102, and the second capacitor element 124. Since the voltage value between both electrodes of the second capacitor element 124 is the voltage value between the gate and the source of the transistor 101, the transistor 101 is turned on when the voltage value becomes equal to the threshold voltage of the transistor 101. It is turned off, and the discharge of the charge held in the capacitor 124 is completed.

Next, the switches 121, 122, 102, and 103 are turned off. Then, the threshold voltage of the transistor 101 is held in the second capacitor 124.

Subsequently, the switch 103 is turned on, and the switches 102, 121, and 122 are turned off. Then, a video signal is output to the wiring 107 and becomes the potential VD of the video signal. In the second capacitor 124, the threshold voltage of the transistor 101 is held; therefore, the gate potential of the transistor 101 is set to the video signal potential VD input from the wiring 107 and the threshold voltage of the transistor 101. The potential (VD + Vth) is obtained by adding (Vth). Accordingly, the transistor 101 is turned on.

When the writing of the video signal is completed, the switch 103 is turned off. Thereafter, the output of the video signal to the wiring 107 is also finished and kept at a constant potential.

Subsequently, the switch 121 is turned on. Since the transistor 101 is already on, current flows from the wiring 108 to the light-emitting element 104 through the switch 121 and the transistor 101. Therefore, the light emitting element 104 emits light. At this time, the value of the current flowing through the light emitting element 104 is in accordance with the voltage value between the gate and the source of the transistor 101. When the potential of the wiring 108 is Va, the voltage value between the gate and the source of the transistor 101 at this time is (Va− (VD + Vth)). Here, even if the threshold voltage (Vth) of the transistor 101 varies between the pixels, a voltage corresponding to the variation is held in the second capacitor element 124 of each pixel. Thus, the luminance of the light-emitting element 104 is not affected by variations in threshold voltage of the transistor 101.

The luminance of the light emitting element as a load is proportional to the current flowing through the light emitting element. Therefore, the present invention for adjusting the magnitude of the current supplied to the light emitting element can easily control the luminance of the light emitting element rather than adjusting the magnitude of the voltage supplied to the light emitting element.

In addition, since the current supplied to the light emitting element is adjusted in the present invention, even if the voltage-current characteristic of the light emitting element changes due to deterioration of the light emitting element or temperature change, the light emitting element has a predetermined amount. Current can flow. Therefore, variation in luminance of the light emitting element can be suppressed.

Further, a switch may be further provided in the pixel configuration shown in FIG. FIG. 25 shows a configuration in which the switch 125 is provided. In FIG. 25A, one terminal of the switch 125 is connected to one terminal of the switch 102, and the other terminal is connected to the first electrode of the light-emitting element 104. An example in which the transistor 165 is used as the switch 125 is illustrated in FIG. In FIG. 25B, the gate of the transistor 165 is connected to the wiring 133, one of the source and the drain is connected to the one connected to the source and drain wiring 109 of the transistor 152, and the other of the source and the drain of the transistor 165 is connected. Is connected to the first electrode of the light emitting element 104.

In the present invention, the second electrode of the light emitting element 104 and the switch 102 (transistor 152) are connected to the common wiring 109. 3A and 3B are cross-sectional views of the pixel. 3A and 3B correspond to the pixel in FIG. 2, and the transistor 101 and the transistor 152 are formed over the substrate 200 with the insulating layer 201 functioning as a base film. In this embodiment, an example in which a top-gate thin film transistor is used as the transistor 101 and the transistor 152 is described; however, a bottom-gate thin film transistor may be used, and the present invention is not limited to this structure.

3A, the transistor 101 includes a semiconductor layer 210, a gate insulating layer 202, a gate 211, a wiring 212a, and a wiring 212b. The transistor 152 includes a semiconductor layer 220, a gate insulating layer 202, a gate 221, and a wiring 222a. And a wiring 222b. Over the transistor 101 and the transistor 152, an insulating layer 203 functioning as an interlayer insulating layer and an insulating layer 204 functioning as a partition wall of the light-emitting element are formed.

The first electrode 230 is formed in contact with the wiring 212b, and the transistor 101 and the light-emitting element 104 are electrically connected to each other. The light-emitting element 104 includes a stack of a first electrode 230, an electroluminescent layer 231, and a second electrode 232. The wiring 109 is formed in contact with the wiring 222b of the transistor 152 over the insulating layer 203 in the same step as the first electrode 230, and the transistor 152 and the wiring 109 are electrically connected. The second electrode 232 of the light-emitting element 104 is in contact with the wiring 109 in an opening (also referred to as a contact hole) formed in the insulating layer 204 so as to reach the wiring 109. The light-emitting element 104 and the wiring 109 are electrically connected to each other. Connected to.

FIG. 3B illustrates an example in which the stacked structure of the wiring 212b of the transistor 101 and the first electrode 230 of the light-emitting element 104 is different from the stacked structure of the wiring 222b and the wiring 109 of the transistor 152 in FIG. It is. In FIG. 3A, the first electrode 230 and the wiring 109 are formed after the wiring 212b and the wiring 222b are formed. On the other hand, in FIG. 3B, the first electrode 230 and the wiring 109 are formed over the insulating layer 203 first, and then the wiring 212b and the wiring 222b are formed. Therefore, in FIGS. 3A and 3B, the stacking order is reversed. 3A has an advantage of preventing contamination such as etching residue on the surface of the first electrode 230. In FIG. 3B, the first electrode 230 is formed in a flat region and the wiring 212b is stacked. Therefore, the covering property is good, and the polishing process such as CMP can be sufficiently performed, so that there is an advantage that it can be formed with good flatness.

FIG. 14 shows an example in which the wiring 109 is manufactured in the same process as the gates of the transistor 152 and the transistor 101 in the display device in FIG. 14A and 14B, the wiring 109 is formed over the gate insulating layer 202. In FIG. 14A, the wiring 222b of the transistor 152 is electrically connected by being formed in contact with the wiring 109 in the opening formed in the insulating layer 203, and the second electrode 232 of the light-emitting element 104 is electrically connected to the wiring 222b. It is electrically connected to the wiring 109 via. 14B illustrates an example in which the second electrode 232 of the light-emitting element 104 is in direct contact with the wiring 109 in openings formed in the insulating layer 203 and the insulating layer 204. The wiring 222b and the second electrode 232 are examples. Are electrically connected via a wiring 109.

FIG. 23 illustrates an example in which the wiring 109 is formed in the same process as the wiring 222b. In FIG. 23, the wiring 109 is manufactured in the same process as the wiring 222b, and the wiring 109 and the wiring 222b also serve as the same common wiring. The second electrode 232 of the light-emitting element 104 is formed in contact with the wiring 222b and the wiring 109, and the wiring 222b, the wiring 109, and the second electrode 232 are electrically connected.

An example in which the insulating layer 206 is formed over the insulating layer 203 as an interlayer insulating layer is illustrated in FIGS. In FIG. 29A, an insulating layer 206 is formed over the transistor 152, the transistor 101, and the insulating layer 203, and a wiring 109 and a first electrode 230 are formed in an opening formed in the insulating layer 206. The wiring 212b of the transistor 101 is electrically connected to the first electrode 230 by being formed in contact with the first electrode 230 in the opening formed in the insulating layer 206. The wiring 222b of the transistor 152 is formed in contact with the wiring 109 in the opening formed in the insulating layer 206, thereby being electrically connected to the wiring 109, and the second electrode 232 of the light-emitting element 104 is connected to the insulating layer 204. By being formed in contact with the wiring 109 in the opening formed in FIG.

FIG. 29B illustrates an example where the connection region between the second electrode 232 and the wiring 109 is wider than that in FIG. As described above, any connection form may be used for the second electrode 232 and the wiring 109. In addition, although FIG. 29 shows an example where the connection location is one location, connection may be made at a plurality of locations, and the shape can be freely set. In this manner, since the transistor 152 and the light-emitting element 104 are only required to be electrically connected to the same wiring 109, the wiring 109 may be manufactured in any process of the display device, and a layout can be freely set.

In the case where a plurality of wirings are connected to each other through a plurality of openings (contact holes) as shown in FIG. 29A, the openings formed in the respective insulating layers may overlap or be shifted. For example, in FIG. 29A, the opening of the insulating layer 203 where the wiring 222b is formed, the opening of the insulating layer 206 where the wiring 109 is formed, and the insulating layer where the second electrode 232 is formed In this example, the opening 204 does not overlap with the opening. Alternatively, a continuous opening may be formed in the insulating layer 203, the insulating layer 206, and the insulating layer 204.

FIG. 12 illustrates an example in which a thin film transistor having an inverted staggered channel etch structure is used as a transistor.

12A, the transistor 141 includes a semiconductor layer 250, a gate insulating layer 242, a semiconductor layer 253a having one conductivity type, a semiconductor layer 253b having one conductivity type, a gate 251, a wiring 252a, and a wiring 252b. The transistor 142 includes a semiconductor layer 260, a semiconductor layer 263a having one conductivity type, a semiconductor layer 263b having one conductivity type, a gate insulating layer 242, a gate 261, a wiring 262a, and a wiring 262b. Over the transistors 141 and 142, an insulating layer 245 functioning as an interlayer insulating layer and an insulating layer 244 functioning as a partition wall of the light-emitting element are formed. In this embodiment, the insulating layer 245 is an example of an inorganic film formed using an inorganic material.

In the opening formed in the insulating layer 245, the wiring 252b and the first electrode 230 are formed in contact with each other, and the transistor 141 and the light-emitting element 104 are electrically connected to each other. The light-emitting element 104 includes a stack of a first electrode 230, an electroluminescent layer 231, and a second electrode 232. The wiring 109 is formed in contact with the wiring 262b of the transistor 142 in an opening formed in the insulating layer 245 in the same step as the first electrode 230, and the transistor 142 and the wiring 109 are electrically connected. The second electrode 232 of the light-emitting element 104 is in contact with the wiring 109 in an opening (also referred to as a contact hole) formed in the insulating layer 244 so as to reach the wiring 109. The light-emitting element 104 and the wiring 109 are electrically connected to each other. Connected to.

12A, amorphous silicon which is an amorphous semiconductor layer is used for the semiconductor layer 250 and the semiconductor layer 260, and n-type conductivity is imparted to the semiconductor layers 253a, 253b, 263a, and 263b having one conductivity type. An example using a semiconductor film is shown. The semiconductor layers 253a, 253b, 263a, and 263b having one conductivity type are not necessarily provided and may be provided as appropriate.

FIG. 12B shows an example in which an insulating layer 246 that is particularly effective as a planarization film is formed over the insulating layer 245. In FIG. 12B, the insulating layer 246 is preferably formed using an organic material in order to planarize unevenness formed by the transistor 142 and the transistor 141.

In FIG. 12B, the wiring 252b and the first electrode 230 are formed in contact with each other in the opening formed in the insulating layer 245 and the insulating layer 246, and the transistor 141 and the light-emitting element 104 are electrically connected to each other. ing. The wiring 109 is formed in contact with the wiring 262b of the transistor 142 in the opening formed in the insulating layer 245 and the insulating layer 246 in the same process as the first electrode 230, and the transistor 142 and the wiring 109 are electrically connected to each other. . The second electrode 232 of the light-emitting element 104 is in contact with the wiring 109 in an opening (also referred to as a contact hole) formed in the insulating layer 244 so as to reach the wiring 109. The light-emitting element 104 and the wiring 109 are electrically connected to each other. Connected to.

As described above, the transistor of the present invention is not particularly limited, and a top gate type or a bottom gate type can be used as appropriate. Also, a planar type or a stagger type may be used.

The second electrode layer of the light-emitting element and the transistor in the pixel are electrically connected by a common wiring. A connection example between the second electrode and the wiring will be described with reference to FIGS.

In FIG. 30A, first electrodes 501a to 501i of a light-emitting element forming a pixel are provided adjacent to each other vertically and horizontally, and insulating layers 503a to 503c functioning as partition walls are formed around each pixel. In FIG. 30A, an opening of an insulating layer is formed between the first electrodes 501a to 501c and the first electrodes 501d to 501f, and the wiring 502a is exposed. Similarly, an opening of an insulating layer is formed between the first electrodes 501d to 501f and the first electrodes 501g to 501i, and the wiring 502b is exposed. The wiring 502a and the wiring 502b formed in the opening of the insulating layer opened so as to divide the pixels in the horizontal direction of the paper surface, and the second electrode formed over the first electrodes 501a to 501i via the electroluminescent layer Are formed in contact with each other and are electrically connected. In FIG. 30A, three pixels included in the first electrode 501d, the first electrode 501e, and the first electrode 501f have a square shape, and the first electrode 501d is red (R). The first electrode 501e may display green (G), and the first electrode 501d may display blue (B). In addition, the pixel shapes in FIGS. 30B, 31A, 31B, and 32A and 32B are examples of pixel shapes to which the present invention can be applied, and are not limited to this embodiment mode. .

In FIG. 30B, first electrodes 511a to 511i of a light-emitting element forming a pixel are provided adjacent to each other vertically and horizontally, and insulating layers 513a to 513c functioning as partition walls are formed around the first electrode of each pixel. Has been. In FIG. 30B, an opening of an insulating layer is formed between the first electrodes 511a, 511d, and 511g and the first electrodes 511b, 511e, and 511h, and the wiring 512a is exposed. Similarly, an opening of an insulating layer is formed between the first electrodes 511b, 511e, and 511h and the first electrodes 511c, 511f, and 511i, and the wiring 512b is exposed. The wiring 512a and the wiring 512b formed in the opening of the insulating layer opened so as to divide the pixels in the vertical direction on the paper surface, and the second electrode formed on the first electrodes 511a to 511i via the electroluminescent layer. Are formed in contact with each other and are electrically connected.

In FIG. 31A, first electrodes 521a to 521i of a light emitting element forming a pixel are provided adjacent to each other vertically and horizontally, and an insulating layer 523 functioning as a partition is formed around the first electrode of each pixel. Yes. An opening of the insulating layer 523 is formed between the first electrode 521c and the first electrode 521f, and the wiring 522a is exposed. Similarly, an opening in the insulating layer 523 is formed between the first electrode 521f and the first electrode 521i, and the wiring 522b is exposed. The wirings 522a and 522b are formed in contact with and electrically connected to the second electrode formed over the first electrodes 521a to 521i through the electroluminescent layer.

In FIG. 31A, an opening with a wiring is not formed continuously in parallel with the pixels as in FIGS. 30A and 30B, but the pixel is a single pixel for a plurality of pixels. The area is reduced and a connection area with wiring is provided. In FIG. 31A, in the first electrode 521d and the first electrode 521e which are pixels in which a connection region with a wiring is not provided, a wide opening portion of the insulating layer 523 can be provided, so that the pixel region can be widened. Therefore, the aperture ratio can be increased. Further, when the display color of the pixel is red (R), green (G), blue (B) (red (R), green (G), blue (B), white (W) may be used), the pixel display The size of the pixel can be set as appropriate depending on the luminance and life of the color, and a more balanced and precise display can be achieved.

In FIG. 31B, first electrodes 531a to 531i of a light-emitting element forming a pixel are provided adjacent to each other vertically and horizontally, and an insulating layer 533 functioning as a partition is formed around the first electrode of each pixel. Yes. Openings of the insulating layer 533 are formed at the positions where the first electrodes 531a to 531f are formed, and the wirings 532a to 532f are exposed. The wirings 532a to 532f are in contact with and electrically connected to the second electrode formed over the first electrodes 531a to 531i via the electroluminescent layer. In this manner, a connection region with a wiring may be provided for each first electrode included in the pixel.

In FIG. 32A, first electrodes 541a to 541c of a light-emitting element forming a pixel are provided adjacent to each other vertically and horizontally, and insulating layers 543a to 543c functioning as partition walls are formed around the first electrode of each pixel. Has been. A plurality of first electrodes of each pixel are arranged vertically, and a pixel region 545c, a pixel region 546c, a pixel region 544a, a pixel region 545a, a pixel region 546a, a pixel region 544b, and a pixel region 545b are adjacent to each other. An insulating layer opening is formed between the pixel region 546c and the pixel region 544a, and the wiring 542a is exposed. Similarly, an opening of an insulating layer is formed between the pixel region 546a and the pixel region 544b, and the wiring 542b is exposed. The wiring 542a and the wiring 542b are formed in contact with and electrically connected to the second electrode formed over the first electrode in the pixel region through the electroluminescent layer.

In FIG. 32A, a wiring is not formed so as to divide each column of pixels as in FIG. 30A, but the second electrode and the wiring are arranged for each of a plurality of pixel regions having a plurality of pixels. The connection area is provided. FIG. 32A illustrates a structure of a display device having RGB display colors, and the pixel region 544a, the pixel region 545a, and the pixel region 546a perform display in R, G, and B display colors, respectively. Therefore, an example in which an opening is provided in the insulating layer for each of the three colors of RGB is shown. Of course, when displaying in RGBW, an insulating layer opening may be provided for every four colors.

FIG. 32B illustrates an example in which an opening is formed in the insulating layer serving as a partition wall in the horizontal direction in FIG. 32A to form a connection region between the second electrode and the wiring. An insulating layer 553a is formed so as to surround the first electrodes 551a to 551c of the light emitting element of the pixel, and an opening of the insulating layer is formed so as to surround the periphery of the insulating layer 553a so that the wiring 552 is exposed. Similarly, an insulating layer 553b is formed so as to surround the first electrodes 554a to 554c, and an opening of the insulating layer is formed so as to surround the periphery of the insulating layer 553b so that the wiring 552 is exposed. The wiring 552 is formed so as to cross every three pixels (in the case of RGB, four may be RGBW) in a grid pattern, and the wiring 552 and the first electrode in the pixel region are interposed via the electroluminescent layer. The second electrode to be formed is in contact with and electrically connected. As described above, the second electrode and the wiring can be connected to each other with any structure, and the structure of the pixel is not limited to this embodiment mode. In addition, each pixel has a stripe arrangement in which pixels corresponding to red, green, and blue are arranged in a stripe pattern, a delta arrangement that is shifted by a half pitch for each line, and sub-pixels that correspond to red, green, and blue are slanted. Any arrangement method of the mosaic arrangement may be adopted. Since the stripe arrangement is suitable for displaying lines, figures, characters, and the like, it is preferably applied to a monitor. The mosaic arrangement is preferably applied to a television set or the like because a more natural image can be obtained than the stripe arrangement. In addition, since the delta arrangement can provide a natural image display, it is preferably applied to a television apparatus or the like.

If there are a large number of wirings that block light emitted from the light emitting element in the pixel, the aperture ratio of the pixel is lowered in the downward-illumination and both-illumination type display devices. In the present invention, the light-emitting element 104 and the switch 102 (transistor 152) are not connected to wirings that are maintained at different constant potentials, but are connected to the same wiring in common. There is no need to provide wiring. Therefore, the number of wirings in the pixel can be reduced and the aperture ratio of the pixel can be improved.

Further, since the wirings are densely installed and the wiring configuration can be complicated and not refined, the process does not have to be complicated. Therefore, shape defects due to complicated processes and pattern shapes can be prevented, and the yield is improved. Therefore, a highly reliable display device can be manufactured at low cost with high productivity.

(Embodiment 2)
A structure of a pixel which is different from that in the above embodiment is described with reference to FIG.

The pixel includes transistors 8010 to 8015, capacitor elements 8016 and 8017, and a light-emitting element 8000. In the above pixel, one of the source and the drain of the transistor 8010 and one of the first electrode and the second electrode of the light-emitting element 8000 are connected to the same wiring 8009.

In the pixel in FIG. 4A, the transistor 8012 and the capacitor elements 8016 and 8017 correspond to the correction circuit 106 in FIG. 1B, and the transistors 8013 and 8015 in the pixel in FIG. This corresponds to the control circuit 105a of (B).

On and off of the transistors 8010 to 8013 and 8015 are controlled by signals input through the wirings 8003 to 8006. Light emission and non-light emission of the light emitting element 8000 are controlled by a video signal input via the wiring 8001. Further, power is supplied to the above-described pixel through a wiring 8002 kept at a constant potential. The conductivity type of the transistor included in the pixel may be either an N-channel type or a P-channel type.

(Embodiment 3)
A structure of a pixel which is different from that in the above embodiment is described with reference to FIG.

The pixel includes transistors 8110 to 8115, a capacitor 8116, and a light-emitting element 8100. In addition, the pixel may further include a capacitor 8117. In the above pixel, one of a source and a drain of the transistor 8110 and one of the first electrode and the second electrode of the light-emitting element 8100 are connected to the same wiring 8109.

In the pixel in FIG. 4B, the transistors 8112 and 8113 and the capacitor elements 8116 and 8117 correspond to the correction circuit 106 in FIG. 1B. The transistor 8115 in the pixel in FIG. This corresponds to the control circuit 105b of (B).

On and off of the transistors 8110 to 8113 and 8115 are controlled by signals input through the wirings 8103 to 8106. Light emission and non-light emission of the light emitting element 8100 are controlled by a video signal input via the wiring 8101. Further, power is supplied to the above-described pixel through a wiring 8102 kept at a constant potential. The conductivity type of the transistor included in the pixel may be either an N-channel type or a P-channel type.

(Embodiment 4)
A structure of a pixel which is different from that in the above embodiment is described with reference to FIG.

The pixel includes transistors 8060 to 8064, a capacitor 8065, and a light-emitting element 8050. Further, the pixel may further include a capacitor 8066. In the above pixel, one of the source and the drain of the transistor 8060 and one of the first electrode and the second electrode of the light-emitting element 8050 are connected to the same wiring 8059.

In the pixel in FIG. 5A, the transistor 8062 and the capacitor elements 8065 and 8066 correspond to the correction circuit 106 in FIG. 1B, and the transistor 8064 in the pixel in FIG. ) Control circuit 105b.

On / off of the transistors 8060 to 8062 and 8064 is controlled by a signal input through the wirings 8053 to 8056. Light emission and non-light emission of the light emitting element 8050 are controlled by a video signal input via the wiring 8051. Further, power is supplied to the above-described pixel through a wiring 8052 which is kept at a constant potential. The conductivity type of the transistor included in the pixel may be either an N-channel type or a P-channel type.

(Embodiment 5)
A structure of a pixel which is different from that in the above embodiment is described with reference to FIG.

The pixel includes transistors 8160 to 8164, a capacitor 8165, and a light-emitting element 8150. In addition, the pixel may further include a capacitor 8166. In the above pixel, one of the source and the drain of the transistor 8160 and one of the first electrode and the second electrode of the light-emitting element 8150 are connected to the same wiring 8159.

In the pixel in FIG. 5B, the transistors 8162 and 8163 and the capacitors 8165 and 8166 correspond to the correction circuit 106 in FIG.

On / off of the transistors 8160 to 8162 is controlled by a signal input through the wirings 8153 to 8155. Light emission and non-light emission of the light emitting element 8150 are controlled by a video signal input through the wiring 8151. In addition, power is supplied to the above-described pixel through a wiring 8152 maintained at a constant potential. The conductivity type of the transistor included in the pixel may be either an N-channel type or a P-channel type.

(Embodiment 6)
A structure of a pixel which is different from that in the above embodiment is described with reference to FIG.

The pixel includes transistors 8210 to 8215, a capacitor 8216, and a light-emitting element 8200. Further, the pixel may further include a capacitor 8217. In the above pixel, one of a source and a drain of the transistor 8210 and one of the first electrode and the second electrode of the light-emitting element 8200 are connected to the same wiring 8209.

In the pixel in FIG. 6A, the transistor 8212 and the capacitor elements 8216 and 8217 correspond to the correction circuit 106 in FIG. 1B, and the transistor 8214 in the pixel in FIG. ) Control circuit 105b.

On / off of the transistors 8210 to 8213 is controlled by signals input through the wirings 8203 to 8205. Light emission and non-light emission of the light emitting element 8200 are controlled by a video signal input through the wiring 8201. Further, power is supplied to the above-described pixel through a wiring 8202 maintained at a constant potential. The conductivity type of the transistor included in the pixel may be either an N-channel type or a P-channel type.

(Embodiment 7)
A structure of a pixel which is different from that in the above embodiment is described with reference to FIG.

The pixel includes transistors 8260 to 8262, a capacitor 8263, and a light-emitting element 8250. In the above pixel, one of the source and the drain of the transistor 8260 and one of the first electrode and the second electrode of the light-emitting element 8250 are connected to the same wiring 8259.

In the pixel in FIG. 6B, the capacitor 8263 corresponds to the correction circuit 106 in FIG.

On and off of the transistor 8261 is controlled by a signal input through the wiring 8253. Light emission and non-light emission of the light emitting element 8250 are controlled by a video signal input through the wiring 8251. In addition, power is supplied to the above-described pixel through a wiring 8252 kept at a constant potential. The conductivity type of the transistor included in the pixel may be either an N-channel type or a P-channel type.

(Embodiment 8)
A structure of a pixel which is different from that in the above embodiment is described with reference to FIG.

The pixel includes transistors 8810 to 8814, capacitor elements 8815 and 8816, and a light emitting element 8800. In the above pixel, one of the source and the drain of the transistor 8810 and one of the first electrode and the second electrode of the light-emitting element 8800 are connected to the same wiring 8809.

In the pixel in FIG. 7A, the transistor 8812 and the capacitors 8815 and 8816 correspond to the correction circuit 106 in FIG. 1B, and the transistor 8813 in the pixel in FIG. ) Control circuit 105a.

On / off of the transistors 8810 to 8813 is controlled by a signal input through the wirings 8803 to 8805. Light emission and non-light emission of the light emitting element 8800 are controlled by a video signal input through the wiring 8801. Further, power is supplied to the above-described pixel through a wiring 8802 which is kept at a constant potential. The conductivity type of the transistor included in the pixel may be either an N-channel type or a P-channel type.

(Embodiment 9)
A structure of a pixel which is different from that in the above embodiment is described with reference to FIG.

The pixel includes transistors 8360 to 8362, a capacitor 8363, and a light-emitting element 8350. In the above pixel, one of a source and a drain of the transistor 8360 and one of the first electrode and the second electrode of the light-emitting element 8350 are connected to the same wiring 8359.

In the pixel in FIG. 7B, the capacitor 8363 corresponds to the correction circuit 106 in FIG.

On / off of the transistor 8361 is controlled by a signal input through the wiring 8353. Light emission and non-light emission of the light emitting element 8350 are controlled by a video signal input through the wiring 8351. Further, power is supplied to the above-described pixel through a wiring 8352 kept at a constant potential. The conductivity type of the transistor included in the pixel may be either an N-channel type or a P-channel type.

(Embodiment 10)
A structure of a pixel which is different from that in the above embodiment is described with reference to FIG.

The pixel includes transistors 8310, 8311, 8313, and 8314, a capacitor 8416, and a light-emitting element 8400. In the above pixel, one of the source and the drain of the transistor 8410 and one of the first electrode and the second electrode of the light-emitting element 8400 are connected to the same wiring 8409.

In the pixel in FIG. 8A, the transistor 8414 and the capacitor 8416 correspond to the correction circuit 106 in FIG. 1B, and the transistor 8413 in the pixel in FIG. 8A has the control in FIG. This corresponds to the circuit 105a, and the transistor 8415 in the pixel in FIG. 8A corresponds to the control circuit 105b in FIG.

On / off of the transistors 8410 to 8415 is controlled by signals input through the wirings 8403 to 8405. Light emission and non-light emission of the light emitting element 8400 are controlled by a video signal input through the wiring 8401. In addition, power is supplied to the above-described pixel through a wiring 8402 that is kept at a constant potential. The conductivity type of the transistor included in the pixel may be either an N-channel type or a P-channel type.

(Embodiment 11)
A structure of a pixel which is different from that in the above embodiment is described with reference to FIG.

The pixel includes transistors 8460 to 8464, a capacitor 8465, and a light-emitting element 8450. In the above pixel, one of a source and a drain of the transistor 8460 and one of the first electrode and the second electrode of the light-emitting element 8450 are connected to the same wiring 8459.

In the pixel in FIG. 8B, the transistor 8462 and the capacitor 8465 correspond to the correction circuit 106 in FIG. 1B. In the pixel in FIG. 8B, the transistor 8463 has the control in FIG. This corresponds to the circuit 105a.

On / off of the transistors 8460 to 8462 is controlled by a signal input through the wirings 8453 to 8455. Light emission and non-light emission of the light emitting element 8450 are controlled by a video signal input through the wiring 8451. In addition, power is supplied to the above-described pixel through a wiring 8452 that is kept at a constant potential. The conductivity type of the transistor included in the pixel may be either an N-channel type or a P-channel type.

(Embodiment 12)
A structure of a pixel which is different from that in the above embodiment is described with reference to FIG.

The pixel includes transistors 8510 to 8517, a capacitor 8518, and a light-emitting element 8500. In the above pixel, one of a source and a drain of the transistor 8510 and one of the first electrode and the second electrode of the light-emitting element 8500 are connected to the same wiring 8509.

In the pixel in FIG. 9A, the transistors 8512, 8513, and 8514 and the capacitor 8518 correspond to the correction circuit 106 in FIG. 1B, and the transistor 8515 in the pixel in FIG. B corresponds to the control circuit 105a in FIG. 9A, and the transistor 8517 in the pixel in FIG. 9A corresponds to the control circuit 105b in FIG.

On / off of the transistors 8510 to 8512, 8514, 8515, and 8517 is controlled by a signal input through the wirings 8503 to 8507. Light emission and non-light emission of the light emitting element 8500 are controlled by a video signal input through the wiring 8501. In addition, power is supplied to the above-described pixel through a wiring 8502 maintained at a constant potential. The conductivity type of the transistor included in the pixel may be either an N-channel type or a P-channel type.

(Embodiment 13)
A structure of a pixel which is different from that in the above embodiment is described with reference to FIG.

The pixel includes transistors 8560 to 8562, a capacitor 8563, and a light-emitting element 8550. In the above pixel, one of the source and the drain of the transistor 8560 and one of the first electrode and the second electrode of the light-emitting element 8550 are connected to the same wiring 8559.

In the pixel in FIG. 9B, the capacitor 8563 corresponds to the correction circuit 106 in FIG.

On / off of the transistors 8560 to 8561 is controlled by a signal input through the wiring 8553. Light emission and non-light emission of the light emitting element 8550 are controlled by a video signal input through the wiring 8551. Further, power is supplied to the above-described pixel through a wiring 8552 that is kept at a constant potential. The conductivity type of the transistor included in the pixel may be either an N-channel type or a P-channel type.

(Embodiment 14)
A structure of a pixel which is different from that in the above embodiment is described with reference to FIG.

The pixel includes switches 8610 to 8615, transistors 8617 and 8618, a capacitor element 8619, and a light emitting element 8600. In the above pixel, one of a source and a drain of the switch 8610 and one of the first electrode and the second electrode of the light-emitting element 8600 are connected to the same wiring 8609.

In the pixel in FIG. 10A, the transistor 8617, the switches 8613 and 8614, and the capacitor 8619 correspond to the correction circuit 106 in FIG. 1A, and the switch 8612 in the pixel in FIG. This corresponds to the control circuit 105a in FIG. 10A, and the switch 8615 in the pixel in FIG. 10A corresponds to the control circuit 105b in FIG.

One terminal of the switch 8611 is connected to the wiring 8601, and one terminal of the switch 8612 is connected to the wiring 8602. The conductivity type of the transistor included in the pixel may be either an N-channel type or a P-channel type.

(Embodiment 15)
A structure of a pixel which is different from that in the above embodiment is described with reference to FIG.

The pixel includes transistors 8660 to 8664, capacitor elements 8665 and 8666, and a light-emitting element 8650. Further, the pixel may further include a capacitor 8667. In the above pixel, one of a source and a drain of the transistor 8660 and one of the first electrode and the second electrode of the light-emitting element 8650 are connected to the same wiring 8659.

In the pixel in FIG. 10B, transistors 8862 and 8663 and capacitors 8665, 8666, and 8667 correspond to the correction circuit 106 in FIG.

On / off of the transistors 8660 to 8862 is controlled by a signal input through the wirings 8654 to 8656. Light emission and non-light emission of the light emitting element 8650 are controlled by a video signal input through the wiring 8651. In addition, power is supplied to the pixels described above by wirings 8852 and 8653 which are kept at a constant potential. The conductivity type of the transistor included in the pixel may be either an N-channel type or a P-channel type.

(Embodiment 16)
A structure of a pixel which is different from that in the above embodiment is described with reference to FIG.

The pixel includes transistors 8710 to 8715, a capacitor 8716, and a light-emitting element 8700. In the above pixel, one of a source and a drain of the transistor 8710 and one of the first electrode and the second electrode of the light-emitting element 8700 are connected to the same wiring 8709.

In the pixel in FIG. 11A, the transistor 8713 and the capacitor 8716 correspond to the correction circuit 106 in FIG. 1B. In the pixel in FIG. 11A, the transistor 8714 has the control in FIG. The transistor 8715 corresponds to the circuit 105a, and the transistor 8715 in the pixel in FIG. 11A corresponds to the control circuit 105b in FIG.

On and off of the transistors 8710, 8711, and 8713 to 8715 are controlled by signals input through wirings 8703 and 8704. Light emission and non-light emission of the light emitting element 8700 are controlled by a video signal input through the wiring 8701. Further, power is supplied to the above-described pixel through a wiring 8702 which is kept at a constant potential. The conductivity type of the transistor included in the pixel may be either an N-channel type or a P-channel type.

(Embodiment 17)
A structure of a pixel which is different from that in the above embodiment is described with reference to FIG.

The pixel includes transistors 8760 to 8762, a capacitor 8765, and a light-emitting element 8750. One of the source and the drain of the transistor 8760 and one of the first electrode and the second electrode of the light-emitting element 8750 are connected to the same wiring 8759 in the above pixel.

In the pixel in FIG. 11B, the transistor 8762 and the capacitor 8765 correspond to the correction circuit 106 in FIG. 1B. In the pixel in FIG. 11B, the transistor 8762 in FIG. This corresponds to the control circuit 105b.

On / off of the transistors 8760, 8761, and 8964 is controlled by a signal input through the wirings 8753 and 8754. Light emission and non-light emission of the light emitting element 8750 are controlled by a video signal input through the wiring 8751. Further, power is supplied to the above-described pixel through a wiring 8752 which is kept at a constant potential. The conductivity type of the transistor included in the pixel may be either an N-channel type or a P-channel type.

(Embodiment 18)
In this embodiment mode, a display device to which the present invention is applied will be described with reference to FIGS.

FIG. 17A is a top view illustrating a structure of a display panel according to the present invention. A pixel portion 2701 in which pixels 2702 are arranged in a matrix over a substrate 2700 having an insulating surface, a scanning line side input terminal 2703, a signal A line side input terminal 2704 is formed. The number of pixels may be provided in accordance with various standards. For full color display using XGA and RGB, 1024 × 768 × 3 (RGB), and for full color display using UXGA and RGB, 1600 × 1200. If it corresponds to x3 (RGB) and full spec high vision and is full color display using RGB, it may be 1920 x 1080 x 3 (RGB).

The pixels 2702 are arranged in a matrix by a scan line extending from the scan line side input terminal 2703 and a signal line extending from the signal line side input terminal 2704 intersecting. Each of the pixels 2702 includes a switching element and a pixel electrode connected to the switching element. A typical example of the switching element is a TFT. By connecting the gate electrode side of the TFT to a scanning line and the source or drain side to a signal line, each pixel can be controlled independently by a signal input from the outside. Yes.

FIG. 17A shows the structure of a display panel in which signals input to the scan lines and signal lines are controlled by an external driver circuit. As shown in FIG. 18A, COG (Chip on The driver IC 2751 may be mounted on the substrate 2700 by a glass method. As another mounting mode, a TAB (Tape Automated Bonding) method as shown in FIG. 18B may be used. The driver IC may be formed on a single crystal semiconductor substrate or may be a circuit in which a TFT is formed on a glass substrate. In FIG. 18, the driver IC 2751 is connected to the FPC 2750.

In the case where a TFT provided for a pixel is formed using a polycrystalline (microcrystalline) semiconductor with high crystallinity, a scan line driver circuit 3702 may be formed over the substrate 3700 as illustrated in FIG. it can. In FIG. 18B, reference numeral 3701 denotes a pixel portion, and the signal line side driver circuit is controlled by an external driver circuit as in FIG. In the case where a TFT provided for a pixel is formed using a polycrystalline (microcrystalline) semiconductor, a single crystal semiconductor, or the like with high mobility, the scan line driver circuit 4702 and the signal line driver circuit 4704 are connected to the substrate 4700 in FIG. It can also be integrally formed on the top.

FIG. 13A shows a top view of the display device shown in this embodiment mode in FIG. 13A and a cross-sectional view taken along line AB in FIG. 13A. 13 includes an external terminal connection region 302, a sealing region 303, a peripheral driver circuit region 304 having a signal line driver circuit, a peripheral driver circuit region 309, a peripheral driver circuit region 307 having a scanning line driver circuit, and a peripheral driver. A circuit area 308 and a connection area 305 are provided.

In this embodiment mode, the circuit is formed as described above. However, the present invention is not limited to this, and an IC chip may be mounted as a peripheral driver circuit by the above-described COG method or TAB method. Further, the scanning line driving circuit and the signal line driving circuit may be plural or singular.

13 in this embodiment mode includes a substrate 300, a thin film transistor 320, a thin film transistor 321, a thin film transistor 322, a thin film transistor 323, a first electrode 386, an electroluminescent layer 388, a second electrode 389, a filler 393, a seal, and the like. Material 392, insulating film 1311a, insulating film 1311b, gate insulating layer 312, insulating film 313, insulating film 314, insulating layer 315, insulating layer 316, sealing substrate 395, wiring 385, wiring 399, wiring 317, and terminal electrode layer 318 , The anisotropic conductive layer 396 and the FPC 394. The display device includes an external terminal connection region 302, a sealing region 303, a peripheral driver circuit region 304, and a pixel region 306.

The thin film transistor 323, the thin film transistor 322, the thin film transistor 321, and the thin film transistor 320 are a semiconductor layer having an impurity region functioning as a source and a drain, a gate insulating layer 312, a gate electrode layer having a stacked structure of two layers, and a source and drain of the semiconductor layer. A wiring that is in contact with and electrically connected to the impurity region is provided.

In the pixel region, the thin film transistor 320 is electrically connected to the first electrode 386 of the light-emitting element 390 through a wiring 399. On the other hand, the second electrode 389 of the light-emitting element 390 is electrically connected to the wiring 385 through an opening formed in the insulating layer 316, and the thin film transistor 321 is connected to a source or drain formed over the insulating film 314. 385 is electrically connected. The wiring 385 corresponds to the wiring 109 in FIG. 1, and the second electrode 389 of the light-emitting element 390 and the thin film transistor 321 are electrically connected through the wiring 385.

If there are a large number of wirings that block light emitted from the light emitting element in the pixel, the aperture ratio of the pixel is lowered in the downward-illumination and both-illumination type display devices. In the present invention, the light-emitting element 390 and the thin film transistor 321 are not connected to wirings maintained at different constant potentials, but are shared, so that it is not necessary to provide a plurality of wirings in a pixel. Therefore, the number of wirings in the pixel can be reduced and the aperture ratio of the pixel can be improved.

Further, since the wirings are densely installed and the wiring configuration can be complicated and not refined, the process does not have to be complicated. Therefore, shape defects due to complicated processes and pattern shapes can be prevented, and the yield is improved. Therefore, a highly reliable display device can be manufactured at low cost with high productivity.

As the substrate 300, a glass substrate, a quartz substrate, a silicon substrate, a metal substrate, or a stainless substrate on which an insulating film is formed may be used. In addition, a plastic substrate having heat resistance that can withstand the processing temperature of this embodiment may be used, or a flexible substrate such as a film may be used. As the plastic substrate, a substrate made of PET (polyethylene terephthalate), PEN (polyethylene naphthalate), or PES (polyethersulfone) can be used, and as the flexible substrate, a synthetic resin such as acrylic can be used.

As the insulating film 311a and the insulating film 311b which function as a base film, an inorganic insulating material and an organic insulating material can be used for the gate insulating layer 312, the insulating film 313, the insulating film 314, the insulating layer 315, and the insulating layer 316. . For example, silicon oxide, silicon nitride, silicon oxynitride, silicon nitride oxide, aluminum oxide, aluminum nitride, aluminum oxynitride, or other inorganic insulating materials can be used. Alternatively, heat-resistant polymers such as acrylic acid, methacrylic acid and derivatives thereof, polyimide, aromatic polyamide, polybenzimidazole, or siloxane resin may be used. Note that a siloxane resin corresponds to a resin including a Si—O—Si bond. Siloxane has a skeleton structure formed of a bond of silicon (Si) and oxygen (O). As a substituent, an organic group containing at least hydrogen (for example, an alkyl group or an aromatic hydrocarbon) is used. A fluoro group may be used as a substituent. Alternatively, an organic group containing at least hydrogen and a fluoro group may be used as a substituent. Moreover, resin materials such as vinyl resins such as polyvinyl alcohol and polyvinyl butyral, epoxy resins, phenol resins, novolac resins, acrylic resins, melamine resins, and urethane resins may be used. Alternatively, an organic material such as benzocyclobutene, parylene, or polyimide, or a composition material containing a water-soluble homopolymer and a water-soluble copolymer may be used. Moreover, an oxazole resin can also be used, for example, photocurable polybenzoxazole or the like can be used. Photocurable polybenzoxazole has a low dielectric constant (dielectric constant 2.9 at room temperature of 1 MHz) and high heat resistance (differential thermal analysis (TGA) thermal decomposition temperature 550 ° C. at a temperature increase of 5 ° C./min. ), A material with low water absorption (0.3% at room temperature for 24 hours).

The insulating film (insulating layer) may be a single layer or a laminated structure of two layers or three layers. In particular, the insulating layer 316 functioning as a partition wall preferably has a shape in which the radius of curvature continuously changes, so that the coverage with the electroluminescent layer 388 and the second electrode 389 formed thereon is improved.

The insulating film (insulating layer) and the semiconductor film included in the thin film transistor 323, the thin film transistor 322, the thin film transistor 321, and the thin film transistor 320 are formed by a sputtering method, a PVD method (Physical Vapor Deposition), a low pressure CVD method (LPCVD method), or plasma CVD. It can be formed by a CVD method (Chemical Vapor Deposition) or the like. In addition, a droplet discharge method, a printing method (a method for forming a pattern such as screen printing or offset printing), a method using a liquid material such as a spin coating method, a dipping method, a dispenser method, or the like can also be used.

A material for forming a semiconductor film (semiconductor layer) included in the thin film transistor 323, the thin film transistor 322, the thin film transistor 321, and the thin film transistor 320 is an amorphous material manufactured by a vapor deposition method or a sputtering method using a semiconductor material gas typified by silane or germane. Semiconductor (hereinafter also referred to as “AS”), polycrystalline semiconductor obtained by crystallizing the amorphous semiconductor using light energy or thermal energy, or semi-amorphous (also referred to as microcrystal or microcrystal; hereinafter referred to as “SAS”) For example, a semiconductor can be used. The semiconductor layer can be formed by a known means (such as sputtering, LPCVD, or plasma CVD).

SAS is a semiconductor having an intermediate structure between amorphous and crystalline structures (including single crystal and polycrystal) and having a third state that is stable in terms of free energy and has a short-range order and a lattice. It includes a crystalline region with strain. The SAS is formed by glow discharge decomposition (plasma CVD) of a silicide gas. As the silicide gas, SiH ₄ , Si ₂ H ₆ , SiH ₂ Cl ₂ , SiHCl ₃ , SiCl ₄ , SiF _4, or the like can be used. Further, F ₂ and GeF ₄ may be mixed. The silicide gas may be diluted with H ₂ , or H ₂ and one or more kinds of rare gas elements selected from He, Ar, Kr, and Ne. In addition, a SAS layer formed of a hydrogen-based gas may be stacked on a SAS layer formed of a fluorine-based gas as a semiconductor layer.

A typical example of an amorphous semiconductor is hydrogenated amorphous silicon, and a typical example of a crystalline semiconductor is polysilicon. Polysilicon (polycrystalline silicon) is mainly made of so-called high-temperature polysilicon using polysilicon formed through a process temperature of 800 ° C. or higher as a main material, or polysilicon formed at a process temperature of 600 ° C. or lower. And so-called low-temperature polysilicon, and polysilicon crystallized by adding an element that promotes crystallization. Of course, as described above, a semi-amorphous semiconductor or a semiconductor including a crystal phase in a part of the semiconductor layer can also be used.

As a semiconductor material, a compound semiconductor such as GaAs, InP, SiC, ZnSe, GaN, or SiGe can be used in addition to a simple substance such as silicon (Si) or germanium (Ge). Alternatively, zinc oxide (ZnO), tin oxide (SnO ₂ ), or the like which is an oxide semiconductor can be used. When ZnO is used for the semiconductor layer, the gate insulating layer is formed of Y ₂ O ₃ , Al ₂ O ₃ , TiO ₂ , A stacked layer of them is preferably used, and ITO, Au, Ti, or the like is preferably used for the gate electrode layer, the source electrode layer, and the drain electrode layer. In addition, In, Ga, or the like can be added to ZnO.

In the case where a crystalline semiconductor layer is used for the semiconductor layer, a method for manufacturing the crystalline semiconductor layer can be a known method (laser crystallization method, thermal crystallization method, or heat using an element that promotes crystallization such as nickel. A crystallization method or the like may be used. In addition, a microcrystalline semiconductor that is a SAS can be crystallized by laser irradiation to improve crystallinity. In the case where an element for promoting crystallization is not introduced, the amorphous silicon film is heated at 500 ° C. for 1 hour in a nitrogen atmosphere before irradiating the amorphous silicon film with laser light, whereby the concentration of hydrogen contained in the amorphous silicon film is set to 1 ×. Release to 10 ²⁰ atoms / cm ³ or less. This is because the film is destroyed when the amorphous silicon film containing a large amount of hydrogen is irradiated with laser light.

The method of introducing the metal element into the amorphous semiconductor layer is not particularly limited as long as the metal element can be present on the surface of the amorphous semiconductor layer or inside the amorphous semiconductor layer. For example, sputtering, CVD, A plasma treatment method (including a plasma CVD method), an adsorption method, or a method of applying a metal salt solution can be used. Among these, the method using a solution is simple and useful in that the concentration of the metal element can be easily adjusted. At this time, in order to improve the wettability of the surface of the amorphous semiconductor layer and to spread the aqueous solution over the entire surface of the amorphous semiconductor layer, irradiation with UV light in an oxygen atmosphere, thermal oxidation method, hydroxy radical It is desirable to form an oxide film by treatment with ozone water or hydrogen peroxide.

Further, in the crystallization step of crystallizing the amorphous semiconductor layer to form the crystalline semiconductor layer, an element for promoting crystallization (also referred to as a catalyst element or a metal element) is added to the amorphous semiconductor layer, and heat treatment ( Crystallization may be carried out at 550 ° C. to 750 ° C. for 3 minutes to 24 hours. As elements for promoting crystallization, metal elements for promoting crystallization of silicon include iron (Fe), nickel (Ni), cobalt (Co), ruthenium (Ru), rhodium (Rh), palladium (Pd). One or a plurality of types selected from osmium (Os), iridium (Ir), platinum (Pt), copper (Cu), and gold (Au) can be used.

In order to remove or reduce the element that promotes crystallization from the crystalline semiconductor layer, a semiconductor layer containing an impurity element is formed in contact with the crystalline semiconductor layer and functions as a gettering sink. As the impurity element, an impurity element imparting n-type conductivity, an impurity element imparting p-type conductivity, a rare gas element, or the like can be used. For example, phosphorus (P), nitrogen (N), arsenic (As), antimony (Sb ), Bismuth (Bi), boron (B), helium (He), neon (Ne), argon (Ar), Kr (krypton), and Xe (xenon) can be used. A semiconductor layer containing a rare gas element is formed over the crystalline semiconductor layer containing an element that promotes crystallization, and heat treatment (at 550 ° C. to 750 ° C. for 3 minutes to 24 hours) is performed. The element that promotes crystallization contained in the crystalline semiconductor layer moves into the semiconductor layer containing a rare gas element, and the element that promotes crystallization in the crystalline semiconductor layer is removed or reduced. After that, the semiconductor layer containing a rare gas element that has become a gettering sink is removed.

The crystallization of the amorphous semiconductor layer may be a combination of heat treatment and crystallization by laser light irradiation, or may be performed multiple times by heat treatment or laser light irradiation alone.

Alternatively, the crystalline semiconductor layer may be directly formed over the substrate by a plasma method. Alternatively, the crystalline semiconductor layer may be selectively formed over the substrate by a plasma method.

As a semiconductor, an organic semiconductor material can be used and formed by a printing method, a spray method, a spin coating method, a droplet discharge method, or the like. In this case, the number of processes can be reduced because the etching process is not necessary. As the organic semiconductor, a low molecular material, a polymer material, or the like is used, and materials such as an organic dye or a conductive polymer material can also be used. As the organic semiconductor material, a π-electron conjugated polymer material whose skeleton is composed of conjugated double bonds is desirable. Typically, a soluble polymer material such as polythiophene, polyfluorene, poly (3-alkylthiophene), a polythiophene derivative, or pentacene can be used.

In addition, as an organic semiconductor material that can be used in the present invention, there is a material that can form a semiconductor layer by processing after forming a soluble precursor. Examples of such an organic semiconductor material include polythienylene vinylene, poly (2,5-thienylene vinylene), polyacetylene, a polyacetylene derivative, and polyarylene vinylene.

When converting the precursor into an organic semiconductor, a reaction catalyst such as hydrogen chloride gas is added as well as heat treatment. Typical solvents for dissolving these soluble organic semiconductor materials include toluene, xylene, chlorobenzene, dichlorobenzene, anisole, chloroform, dichloromethane, γ-butyllactone, butyl cellosolve, cyclohexane, NMP (N-methyl-2 -Pyrrolidone), cyclohexanone, 2-butanone, dioxane, dimethylformamide (DMF), THF (tetrahydrofuran), or the like can be applied.

The gate electrode can be formed by a CVD method, a sputtering method, a droplet discharge method, or the like. The gate electrode layer is an element selected from Ag, Au, Cu, Ni, Pt, Pd, Ir, Rh, W, Al, Ta, Mo, Cd, Zn, Fe, Ti, Si, Ge, Zr, Ba, Alternatively, an alloy material or a compound material containing the element as a main component may be used. Alternatively, a semiconductor film typified by a polycrystalline silicon film doped with an impurity element such as phosphorus, or an AgPdCu alloy may be used. Alternatively, a single-layer structure or a multi-layer structure may be employed, for example, a two-layer structure of a tungsten nitride film and a molybdenum film, a tungsten film with a thickness of 50 nm, an alloy of aluminum and silicon with a thickness of 500 nm (Al- A three-layer structure in which a Si) film and a titanium nitride film with a thickness of 30 nm are sequentially stacked may be employed. In the case of a three-layer structure, tungsten nitride may be used instead of tungsten of the first conductive film, or aluminum instead of the aluminum and silicon alloy (Al-Si) film of the second conductive film. A titanium alloy film (Al—Ti) may be used, or a titanium film may be used instead of the titanium nitride film of the third conductive film.

A light-transmitting material having a property of transmitting visible light can be used for the gate electrode. As the light-transmitting conductive material, indium tin oxide (ITO), indium tin oxide containing silicon oxide (ITSO), organic indium, organic tin, zinc oxide, or the like can be used. In addition, indium zinc oxide (IZO) containing zinc oxide (ZnO), zinc oxide (ZnO), ZnO doped with gallium (Ga), tin oxide (SnO ₂ ), tungsten oxide is included. Indium oxide, indium zinc oxide containing tungsten oxide, indium oxide containing titanium oxide, indium tin oxide containing titanium oxide, or the like may also be used.

In the case where processing is required by etching to form the gate electrode, a mask may be formed and processed by dry etching or wet etching. Using an ICP (Inductively Coupled Plasma) etching method, the etching conditions (the amount of power applied to the coil-type electrode, the amount of power applied to the substrate-side electrode, the electrode temperature on the substrate side, etc.) are appropriately set. By adjusting, the electrode layer can be etched into a tapered shape. As an etching _gas, using Cl _2, BCl 3, SiCl ₄ or a chlorine-based gas typified by CCl _4, fluorine-based gas or _{O 2} and typified by CF 4, SF ₆ or NF ₃ as appropriate be able to.

Further, after forming a substrate, an insulating layer, a semiconductor layer, a gate insulating layer, an interlayer insulating layer, other insulating layers constituting a display device, a conductive layer, etc., the substrate is subjected to oxidation or nitridation using plasma treatment, The surfaces of the insulating layer, semiconductor layer, gate insulating layer, and interlayer insulating layer may be oxidized or nitrided. When a semiconductor layer or an insulating layer is oxidized or nitrided using plasma treatment, the surface of the semiconductor layer or the insulating layer is modified, so that the insulating layer becomes denser than an insulating layer formed by a CVD method or a sputtering method. be able to. Therefore, defects such as pinholes can be suppressed and the characteristics of the display device can be improved. The plasma treatment as described above can also be performed on a conductive layer such as a gate electrode or a wiring, and can be nitrided or oxidized on the surface by performing nitridation or oxidation (or both nitridation and oxidation).

The plasma treatment is performed in an atmosphere of the gas at an electron density of 1 × 10 ¹¹ cm ⁻³ or more and an electron temperature of plasma of 1.5 eV or less. More specifically, the electron density is 1 × 10 ¹¹ cm ^{−3 to} 1 × 10 ¹³ cm ⁻³ and the electron temperature of plasma is 0.5 eV to 1.5 eV. Since the electron density of the plasma is high and the electron temperature in the vicinity of the object to be processed formed on the substrate is low, damage to the object to be processed by the plasma can be prevented. In addition, since the electron density of plasma is as high as 1 × 10 ¹¹ cm ⁻³ or higher, an oxide film or a nitride film formed by oxidizing or nitriding an object to be irradiated using plasma treatment is a CVD method. Compared with a film formed by sputtering or the like, a film having excellent uniformity in film thickness and the like and a dense film can be formed. In addition, since the electron temperature of plasma is as low as 1.5 eV or less, oxidation or nitridation can be performed at a lower temperature than conventional plasma treatment or thermal oxidation. For example, even if the plasma treatment is performed at a temperature lower by 100 degrees or more than the strain point of the glass substrate, the oxidation or nitridation treatment can be sufficiently performed. Note that a high frequency such as a microwave (2.45 GHz) can be used as a frequency for forming plasma. Note that the plasma treatment is performed using the above conditions unless otherwise specified.

Although the single gate structure is described in this embodiment mode, a multi-gate structure such as a double gate structure may be used. In this case, a gate electrode layer may be provided above and below the semiconductor layer, or a plurality of gate electrode layers may be provided only on one side (above or below) of the semiconductor layer. The semiconductor layer may have impurity regions with different concentrations. For example, the vicinity of the channel region of the semiconductor layer and the region stacked with the gate electrode layer may be a low concentration impurity region, and the region outside the channel region may be a high concentration impurity region.

The wiring connected to the thin film transistors 320 to 323, the wiring 385, the wiring 399, the wiring 317, and the terminal electrode layer 318 are formed by forming a conductive film by a PVD method, a CVD method, an evaporation method, or the like and then etching into a desired shape. be able to. Further, the source electrode layer or the drain electrode layer can be selectively formed at a predetermined place by a printing method, an electroplating method, or the like. Furthermore, a reflow method or a damascene method may be used. The source electrode layer or drain electrode layer is made of Ag, Au, Cu, Ni, Pt, Pd, Ir, Rh, W, Al, Ta, Mo, Cd, Zn, Fe, Ti, Zr, Ba or other metals, A semiconductor such as Si or Ge, an alloy thereof, or a nitride thereof may be used. A light-transmitting material can also be used.

Further, in the case of a light-transmitting conductive material, indium tin oxide (ITO), indium tin oxide containing silicon oxide (ITSO), indium zinc oxide containing zinc oxide (ZnO) (IZO (indium zinc oxide) )), Zinc oxide (ZnO), ZnO doped with gallium (Ga), tin oxide (SnO ₂ ), indium oxide containing tungsten oxide, indium zinc oxide containing tungsten oxide, indium oxide containing titanium oxide Indium tin oxide containing titanium oxide or the like can be used.

The first electrode 386 (also referred to as a pixel electrode) functions as an anode or a cathode, and is an element selected from Ti, Ni, W, Cr, Pt, Zn, Sn, In, or Mo, or TiN, TiSi _{X N Y, WSi X, WN X} , WSi X N Y, a film or a laminate film thereof as a main component an alloy material or a compound material containing the element as its main component, such as NbN in total thickness of 100nm~800nm Use it.

A transparent conductive film formed using a light-transmitting conductive material can be used for the first electrode 386; indium oxide containing tungsten oxide, indium zinc oxide containing tungsten oxide, or indium containing titanium oxide. An oxide, indium tin oxide containing titanium oxide, or the like can be used. Needless to say, indium tin oxide (ITO), indium zinc oxide (IZO), indium tin oxide added with silicon oxide (ITSO), or the like can also be used.

An example of the composition ratio of each light-transmitting conductive material will be described. The composition ratio of indium oxide containing tungsten oxide may be 1.0 wt% tungsten oxide and 99.0 wt% indium oxide. The composition ratio of indium zinc oxide containing tungsten oxide may be 1.0 wt% tungsten oxide, 0.5 wt% zinc oxide, and 98.5 wt% indium oxide. The indium oxide containing titanium oxide may be 1.0 wt% to 5.0 wt% titanium oxide and 99.0 wt% to 95.0 wt% indium oxide. The composition ratio of indium tin oxide (ITO) may be 10.0 wt% tin oxide and 90.0 wt% indium oxide. The composition ratio of indium zinc oxide (IZO) may be 10.7 wt% zinc oxide and 89.3 wt% indium oxide. The composition ratio of indium tin oxide containing titanium oxide may be 5.0 wt% titanium oxide, 10.0 wt% tin oxide, and 85.0 wt% indium oxide. The above composition ratio is an example, and the ratio of the composition ratio may be set as appropriate.

Further, even when a material such as a metal film that does not have translucency is used, the first film thickness can be reduced by thinning (preferably about 5 nm to 30 nm) so that light can be transmitted. It becomes possible to emit light from the electrode 386. As the metal thin film that can be used for the first electrode 386, a conductive film made of titanium, tungsten, nickel, gold, platinum, silver, aluminum, magnesium, calcium, lithium, or an alloy thereof can be used. it can.

The first electrode 386 can be formed by an evaporation method, a sputtering method, a CVD method, a printing method, a dispenser method, a droplet discharge method, or the like.

The first electrode 386 may be cleaned by polishing with a CMP method or a polyvinyl alcohol-based porous body so that the surface thereof is planarized. Further, after polishing using the CMP method, the surface of the first electrode 386 may be subjected to ultraviolet irradiation, oxygen plasma treatment, or the like.

Heat treatment may be performed after the first electrode 386 is formed. By this heat treatment, moisture contained in the first electrode 386 is released. Therefore, the first electrode 386 does not cause degassing. Therefore, even when a light-emitting material that easily deteriorates due to moisture is formed over the first electrode, the light-emitting material does not deteriorate, and a highly reliable display device is manufactured. can do.

The electroluminescent layer 388 can be selectively formed using a material that emits red (R), green (G), or blue (B) light by an evaporation method using an evaporation mask. Alternatively, the electroluminescent layer may be formed using a material that emits white (W) light. A material that emits red (R), green (G), and blue (B) light can also be formed by a droplet discharge method (such as a low-molecular or high-molecular material). This is preferable because it can be applied separately.

As the second electrode 389, Al, Ag, Li, Ca, or an alloy or compound thereof such as MgAg, MgIn, AlLi, CaF ₂ , or calcium nitride can be used.

An insulating layer may be provided over the second electrode 389 as a passivation film (protective film). Thus, it is effective to provide a passivation film so as to cover the second electrode 389. As the passivation film, silicon nitride, silicon oxide, silicon oxynitride, silicon nitride oxide, aluminum nitride, aluminum oxynitride, aluminum nitride oxide or aluminum oxide having a nitrogen content higher than the oxygen content, diamond-like carbon (DLC), The insulating film includes a nitrogen-containing carbon film, and a single layer or a combination of the insulating films can be used. Alternatively, a siloxane resin may be used.

At this time, it is preferable to use a film with good coverage as the passivation film, and it is effective to use a carbon film, particularly a DLC film. Since the DLC film can be formed in a temperature range from room temperature to 100 ° C., it can be easily formed over the electroluminescent layer 388 having low heat resistance. The DLC film is formed by plasma CVD (typically, RF plasma CVD, microwave CVD, electron cyclotron resonance (ECR) CVD, hot filament CVD, etc.), combustion flame, sputtering, ion beam evaporation. It can be formed by laser vapor deposition. The reaction gas used for film formation was hydrogen gas and a hydrocarbon-based gas (for example, CH ₄ , C ₂ H ₂ , C ₆ H _6, etc.), ionized by glow discharge, and negative self-bias was applied. Films are formed by accelerated collision of ions with the cathode. The CN film may be formed using C ₂ H ₄ gas and N ₂ gas as reaction gases. The DLC film has a high blocking effect against oxygen and can suppress oxidation of the electroluminescent layer 388. Therefore, the problem that the electroluminescent layer 388 is oxidized during the subsequent sealing process can be prevented.

The substrate 300 over which the light-emitting element 390 is formed and the sealing substrate 395 are fixed to each other with a sealant 392, and the light-emitting element is sealed. As the sealant 392, it is typically preferable to use a visible light curable resin, an ultraviolet curable resin, or a thermosetting resin. For example, bisphenol A type liquid resin, bisphenol A type solid resin, bromine-containing epoxy resin, bisphenol F type resin, bisphenol AD type resin, phenol type resin, cresol type resin, novolac type resin, cyclic aliphatic epoxy resin, epibis type epoxy Epoxy resins such as resins, glycidyl ester resins, glycidylamine resins, heterocyclic epoxy resins, and modified epoxy resins can be used. Note that a region surrounded by the sealant may be filled with a filler 393, or nitrogen or the like may be sealed by sealing in a nitrogen atmosphere. In the case of the downward emission type, the filler 393 does not need to have a light-transmitting property, but in the case of a structure in which light is extracted through the filler 393, the filler 393 needs to have a light-transmitting property. Typically, a visible light curable, ultraviolet curable, or thermosetting epoxy resin may be used. Through the above steps, a display device having a display function using a light-emitting element in this embodiment is completed. Further, the filler can be dropped in a liquid state and filled in the display device. When a material having hygroscopicity such as a desiccant is used as the filler, a further water absorption effect can be obtained and deterioration of the element can be prevented.

A desiccant is installed in the display device to prevent deterioration of the element due to moisture. In this embodiment mode, the desiccant is provided in a recess formed in the sealing substrate so as to surround the pixel region, and the display device is not hindered from being thinned. Moreover, if a desiccant is formed also in the area | region corresponding to wiring and a water absorption area is taken widely, the water absorption effect will be high. Further, since the desiccant is formed on the wiring that does not directly emit light, the light extraction efficiency is not lowered.

Note that in this embodiment mode, a case where a light-emitting element is sealed with a glass substrate is shown; however, the sealing process is a process for protecting the light-emitting element from moisture and is mechanically sealed with a cover material. Any of a method, a method of encapsulating with a thermosetting resin or an ultraviolet light curable resin, or a method of encapsulating with a thin film having a high barrier ability such as a metal oxide or a metal nitride is used. As the cover material, glass, ceramics, plastic, or metal can be used. However, when light is emitted to the cover material side, it must be translucent. In addition, the cover material and the substrate on which the light emitting element is formed are bonded together using a sealing material such as a thermosetting resin or an ultraviolet light curable resin, and the resin is cured by heat treatment or ultraviolet light irradiation treatment to form a sealed space. Form. It is also effective to provide a hygroscopic material typified by barium oxide in this sealed space. This hygroscopic material may be provided in contact with the sealing material, or may be provided on the partition wall or in the peripheral portion so as not to block light from the light emitting element. Further, the space between the cover material and the substrate on which the light emitting element is formed can be filled with a thermosetting resin or an ultraviolet light curable resin. In this case, it is effective to add a moisture absorbing material typified by barium oxide in the thermosetting resin or the ultraviolet light curable resin.

If there are a large number of wirings that block light emitted from the light emitting element in the pixel, the aperture ratio of the pixel is lowered in the downward-illumination and both-illumination type display devices. In the present invention, the light-emitting element 390 and the thin film transistor 321 are not connected to wirings maintained at different constant potentials, but are connected to the same wiring and used in common, so that it is necessary to provide a plurality of wirings in the pixel. Disappears. Therefore, the number of wirings in the pixel can be reduced and the aperture ratio of the pixel can be improved.

Further, since the wirings are densely installed and the wiring configuration can be complicated and not refined, the process does not have to be complicated. Therefore, shape defects due to complicated processes and pattern shapes can be prevented, and the yield is improved. Therefore, a highly reliable display device can be manufactured at low cost with high productivity.

This embodiment mode can be used in combination with each of Embodiment Modes 1 to 17.

(Embodiment 19)
Although a display device including a light-emitting element can be formed by applying the present invention, light emitted from the light-emitting element performs any one of downward emission, upward emission, and both emission. The light emitted from the light emitting element is either a downward emission that extracts light from the substrate having the element, an upward emission that emits light from the sealing substrate side, or a dual emission that emits light from both substrates sandwiching the light emitting element. . Here, a stacked structure of light-emitting elements corresponding to each case will be described with reference to FIGS.

In this embodiment, an example in which an inverted staggered thin film transistor is used as a thin film transistor used for a pixel is described. A transistor that can be used in the present invention is not particularly limited, and may have a top-gate structure or a bottom-gate structure as described in this embodiment. There are two types of inverted staggered thin film transistors: a channel etch type and a channel protective type. In this embodiment, an example in which a channel protective type reverse staggered thin film transistor including a channel protective layer is used is described. In addition, an example in which an insulating layer functioning as a partition is formed over the transistor and an interlayer insulating layer is not formed between the transistor and the partition is shown.

In the present invention, a conductive layer for forming a wiring layer or an electrode layer, a mask layer for forming a predetermined pattern, or the like may be formed by a method capable of selectively forming a pattern such as a droplet discharge method. . A droplet discharge (ejection) method (also called an ink-jet method depending on the method) is a method in which a droplet of a composition prepared for a specific purpose is selectively ejected (ejection) to form a predetermined pattern (such as a conductive layer or a conductive layer). An insulating layer or the like can be formed. At this time, a process for controlling wettability and adhesion may be performed on the formation region. In addition, a method by which a pattern can be transferred or drawn, for example, a printing method (a method for forming a pattern such as screen printing or offset printing), a dispenser method, or the like can be used.

When forming a film (insulating film, conductive film, or the like) using a droplet discharge method, a composition containing a film material processed into particles is discharged, and is fused and fused and solidified by firing. A film is formed. In a film formed by discharging and baking a composition containing a conductive material in this manner, a film formed by a sputtering method or the like often has a columnar structure, but has many grain boundaries. Often exhibits a polycrystalline state. In addition, since it adheres to the formation region in a liquid state having fluidity, the shape of the liquid state may be reflected and the surface may have a gentle curvature.

The droplet discharge means used in the droplet discharge method is a general term for a device having means for discharging droplets such as a nozzle having a composition discharge port and a head having one or a plurality of nozzles. The diameter of the nozzle provided in the droplet discharge means is set to 0.02 to 100 μm (preferably 30 μm or less), and the discharge amount of the composition discharged from the nozzle is 0.001 pl to 100 pl (preferably 0). .1pl or more and 40pl or less, more preferably 10pl or less). The discharge amount increases in proportion to the size of the nozzle diameter. In addition, the distance between the object to be processed and the nozzle outlet is preferably as close as possible in order to drop it at a desired location, preferably about 0.1 to 3 mm (preferably about 1 mm or less). Set.

A composition in which a conductive material is dissolved or dispersed in a solvent is used as the composition discharged from the discharge port. The conductive material corresponds to fine particles or dispersible nanoparticles of metals such as Ag, Au, Cu, Ni, Pt, Pd, Ir, Rh, W, and Al, and includes metal sulfides of Cd and Zn, Fe, Ti Further, oxides such as Si, Ge, Zr and Ba, fine particles such as silver halide or dispersible nanoparticles may be mixed. The conductive material may also be used as a mixture. As the transparent conductive film, indium tin oxide (ITO), indium tin oxide containing silicon oxide (ITSO), organic indium, organic tin, zinc oxide (ZnO), titanium nitride, or the like can be used. Further, indium zinc oxide containing zinc oxide (IZO (indium zinc oxide)), ZnO doped with gallium (Ga), tin oxide (SnO ₂ ), indium oxide containing tungsten oxide, indium containing tungsten oxide Zinc oxide, indium oxide containing titanium oxide, indium tin oxide containing titanium oxide, or the like may also be used. However, it is preferable to use a composition in which any of gold, silver and copper is dissolved or dispersed in a solvent in consideration of the specific resistance value, more preferably the composition discharged from the discharge port. It is preferable to use low resistance silver or copper. However, when silver or copper is used, a barrier film may be provided as a countermeasure against impurities. As the barrier film, a silicon nitride film or a nickel boron (NiB) film can be used.

The composition to be discharged is obtained by dissolving or dispersing a conductive material in a solvent, but additionally contains a dispersant and a thermosetting resin called a binder. In particular, the binder has a function of preventing cracks and non-uniform shape changes during firing. Thus, the formed conductive layer may contain an organic material. The organic material contained varies depending on the heating temperature, atmosphere, and time. This organic material is a metal particle binder, a solvent, a dispersant, an organic resin that functions as a coating agent, etc., and typically, polyimide, acrylic, novolac resin, melamine resin, phenol resin, epoxy resin, silicon resin , Furan resin, diallyl phthalate resin and the like.

Alternatively, particles in which a conductive material is coated with another conductive material to form a plurality of layers may be used. For example, particles having a three-layer structure in which nickel boron (NiB) is coated around copper and silver is coated around it may be used. As the solvent, esters such as butyl acetate and ethyl acetate, alcohols such as isopropyl alcohol and ethyl alcohol, organic solvents such as methyl ethyl ketone and acetone, and water are used. The viscosity of the composition is preferably 20 mPa · s (cp) or less, which is to prevent drying from occurring during discharge and to allow the composition to be smoothly discharged from the discharge port. The surface tension of the composition is preferably 40 mN / m or less. However, the viscosity and the like of the composition may be appropriately adjusted according to the solvent to be used and the application. As an example, the viscosity of a composition in which ITO, organic indium, or organic tin is dissolved or dispersed in a solvent is 5 to 20 mPa · s, the viscosity of a composition in which silver is dissolved or dispersed in a solvent is 5 to 20 mPa · s, The viscosity of the composition in which gold is dissolved or dispersed in a solvent is preferably set to 5 to 20 mPa · s.

The conductive layer may be a stack of a plurality of conductive materials. Alternatively, first, silver may be used as a conductive material, and a conductive layer may be formed by a droplet discharge method, followed by plating with copper or the like. Plating may be performed by electroplating or chemical (electroless) plating. For plating, the substrate surface may be immersed in a container filled with a solution having a plating material, but the substrate is placed at an angle (or vertically) so that the solution having the material to be plated flows on the substrate surface. It may be applied. When plating is performed so that the solution is applied while standing the substrate, there is an advantage that the process apparatus is reduced in size.

Although depending on the diameter of each nozzle and the desired pattern shape, the diameter of the conductor particles is preferably as small as possible for preventing nozzle clogging and producing a high-definition pattern. A particle size of 1 μm or less is preferred. The composition is formed by a method such as an electrolytic method, an atomizing method, or a wet reduction method, and its particle size is generally about 0.01 to 10 μm. However, when formed in a gas evaporation method, the nanomolecules protected with the dispersant are as fine as about 7 nm. When the surface of each particle is covered with a coating agent, the nanoparticles are aggregated in the solvent. And stably disperse at room temperature and shows almost the same behavior as liquid. Therefore, it is preferable to use a coating agent.

The step of discharging the composition may be performed under reduced pressure. It is preferable to perform under reduced pressure because an oxide film or the like is not formed on the surface of the conductive layer. After discharging the composition, one or both steps of drying and baking are performed. The drying and firing steps are both heat treatment steps. For example, drying is performed at 100 degrees for 3 minutes, and firing is performed at 200 to 350 degrees for 15 minutes to 60 minutes. Time is different. The drying process and the firing process are performed under normal pressure or reduced pressure by laser light irradiation, rapid thermal annealing, a heating furnace, or the like. In addition, the timing which performs this heat processing is not specifically limited. In order to satisfactorily perform the drying and firing steps, the substrate may be heated, and the temperature at that time depends on the material of the substrate or the like, but is generally 100 to 800 degrees (preferably 200). ~ 350 degrees). By this step, the solvent in the composition is volatilized or the dispersant is chemically removed, and the surrounding resin is cured and contracted to bring the nanoparticles into contact with each other, thereby accelerating fusion and fusion.

For the laser light irradiation, a continuous wave or pulsed gas laser or solid-state laser may be used. Examples of the former gas laser include an excimer laser and a YAG laser, and examples of the latter solid-state laser include a laser using a crystal such as YAG, YVO ₄ , and GdVO ₄ doped with Cr, Nd, or the like. . Note that it is preferable to use a continuous wave laser because of the absorption rate of the laser light. Further, a laser irradiation method combining pulse oscillation and continuous oscillation may be used. However, depending on the heat resistance of the substrate, the heat treatment by laser light irradiation may be performed instantaneously within a few microseconds to several tens of seconds so as not to destroy the substrate. Instantaneous thermal annealing (RTA) uses an infrared lamp or a halogen lamp that irradiates ultraviolet light or infrared light in an inert gas atmosphere, and rapidly raises the temperature for several minutes to several microseconds. This is done by applying heat instantaneously. Since this treatment is performed instantaneously, only the outermost thin film can be heated substantially without affecting the lower layer film. That is, it does not affect a substrate having low heat resistance such as a plastic substrate.

Further, after a liquid composition is discharged by a droplet discharge method to form an object to be formed, the surface may be flattened by pressing with pressure in order to improve the flatness. As a pressing method, unevenness may be reduced by scanning a roller-shaped object on the surface or pressing the surface vertically with a flat plate-like object. A heating step may be performed when pressing. Alternatively, the surface may be softened or dissolved with a solvent or the like, and the surface irregularities may be removed with an air knife. Further, polishing may be performed using a CMP method. This step can be applied when the surface is flattened when unevenness is generated by the droplet discharge method.

Although the method for forming a film by the droplet discharge method has been described using a conductive layer as an example, conditions such as discharge, drying, baking, and solvent, and detailed description also apply to the insulating layer formed in this embodiment. can do. By combining the droplet discharge method, the cost can be reduced as compared with the entire surface coating formation by a spin coating method or the like.

FIG. 16 is a cross-sectional view illustrating a light-emitting element and a transistor functioning as a driving transistor connected to the light-emitting element. Light emitted from the light-emitting element is emitted in the direction of an arrow in the drawing. Note that the substrate used for sealing is omitted in FIG.

In each pixel in FIGS. 16A to 16C, the transistor 481, the transistor 461, and the transistor 471 are inverted staggered thin film transistors that are manufactured in the same manner. Therefore, although the transistor 481 is described as an example, the transistor 461 and the transistor 471 have a similar structure.

The transistor 481 is provided over a light-transmitting substrate 480, and includes a gate electrode layer 493, a gate insulating film 497, a semiconductor layer 494, an n-type semiconductor layer 495a, an n-type semiconductor layer 495b, a source electrode layer, or A drain electrode layer 487a, a source or drain electrode layer 487b, and a channel protective layer 496 are formed.

In this embodiment, a crystalline semiconductor layer is used as the semiconductor layer, and an n-type semiconductor layer is used as the one-conductivity-type semiconductor layer. Instead of forming an n-type semiconductor layer, conductivity may be imparted to the semiconductor layer by performing plasma treatment with a PH ₃ gas. The semiconductor layer is not limited to this embodiment mode, and an amorphous semiconductor layer can also be used. In the case where a crystalline semiconductor layer such as polysilicon is used as in this embodiment mode, an impurity having one conductivity type is formed by introducing (adding) an impurity into the crystalline semiconductor layer without forming a one conductivity type semiconductor layer. A region may be formed. In addition, an organic semiconductor such as pentacene can be used. When the organic semiconductor is selectively formed by a droplet discharge method or the like, an etching process to a desired shape can be simplified.

In this embodiment, an amorphous semiconductor layer is crystallized as the semiconductor layer 494 to form a crystalline semiconductor layer. In the crystallization step, an element (also referred to as a catalyst element or a metal element) that promotes crystallization is added to the amorphous semiconductor layer, and crystallization is performed by heat treatment (at 550 ° C. to 750 ° C. for 3 minutes to 24 hours). As elements for promoting crystallization, metal elements for promoting crystallization of silicon include iron (Fe), nickel (Ni), cobalt (Co), ruthenium (Ru), rhodium (Rh), palladium (Pd). One or plural types selected from osmium (Os), iridium (Ir), platinum (Pt), copper (Cu), and gold (Au) can be used. In this embodiment, nickel is used.

In order to remove or reduce the element that promotes crystallization from the crystalline semiconductor layer, a semiconductor layer containing an impurity element is formed in contact with the crystalline semiconductor layer and functions as a gettering sink. As the impurity element, an impurity element imparting n-type conductivity, an impurity element imparting p-type conductivity, a rare gas element, or the like can be used. For example, phosphorus (P), nitrogen (N), arsenic (As), antimony (Sb ), Bismuth (Bi), boron (B), helium (He), neon (Ne), argon (Ar), Kr (krypton), and Xe (xenon) can be used. In this embodiment, a semiconductor layer including an impurity element functioning as a gettering sink is formed using an n-type semiconductor layer including phosphorus (P) that is an impurity element imparting n-type conductivity. An n-type semiconductor layer is formed over the crystalline semiconductor layer containing an element that promotes crystallization, and heat treatment (at 550 ° C. to 750 ° C. for 3 minutes to 24 hours) is performed. The element that promotes crystallization contained in the crystalline semiconductor layer moves into the semiconductor layer having n-type, and the element that promotes crystallization in the crystalline semiconductor layer is removed or reduced. It is formed. On the other hand, the n-type semiconductor layer becomes an n-type semiconductor layer containing a metal element which is an element that promotes crystallinity, and then processed into a semiconductor layer 495a having an n-type and a semiconductor layer having an n-type. 495b. Thus, the n-type semiconductor layer functions as a gettering sink of the semiconductor layer 494 and also functions as a source region and a drain region as it is.

In this embodiment mode, the crystallization step and the gettering step of the semiconductor layer are performed by a plurality of heat treatments; however, the crystallization step and the gettering step can be performed by a single heat treatment. In this case, an amorphous semiconductor layer is formed, an element that promotes crystallization is added, a semiconductor layer serving as a gettering sink is formed, and then heat treatment is performed.

In this embodiment, the gate insulating layer is formed by stacking a plurality of layers, and a silicon nitride oxide film and a silicon oxynitride film are formed as the gate insulating film 497 from the gate electrode layer 493 side to have a two-layer stacked structure. The insulating layers to be stacked are preferably formed continuously while switching the reaction gas at the same temperature without breaking the vacuum in the same chamber. If formed continuously without breaking the vacuum, it is possible to prevent the interface between the stacked films from being contaminated.

For the channel protective layer 496, polyimide, polyvinyl alcohol, or the like may be dropped by a droplet discharge method. As a result, the exposure process can be omitted. Channel protective layers include inorganic materials (silicon oxide, silicon nitride, silicon oxynitride, silicon nitride oxide, etc.), photosensitive or non-photosensitive organic materials (organic resin materials) (polyimide, acrylic, polyamide, polyimide amide, benzo Cyclobutene, etc.), resist, low dielectric constant material, etc., or a film made of a plurality of types, or a laminate of these films can be used. A siloxane resin material may be used. As a manufacturing method, a vapor deposition method such as a plasma CVD method or a thermal CVD method, or a sputtering method can be used. Alternatively, a droplet discharge method or a printing method (a method for forming a pattern such as screen printing or offset printing) can be used. A thin film obtained by a spin coating method can also be used.

First, the case where radiation is performed toward the substrate 480 side, that is, the case where downward radiation is performed will be described with reference to FIG. In this case, the first electrode layer 484, the electroluminescent layer 485, and the second electrode layer 486 are sequentially stacked in contact with the source or drain electrode layer 487b so as to be electrically connected to the transistor 481. The substrate 480 through which light is transmitted needs to have a light-transmitting property with respect to at least light in the visible region. Next, the case where radiation is performed on the side opposite to the substrate 460, that is, the case where upward radiation is performed will be described with reference to FIG. The transistor 461 can be formed in a manner similar to that of the thin film transistor described above.

A source or drain electrode layer 462 which is electrically connected to the transistor 461 is in contact with and electrically connected to the first electrode layer 463. A first electrode layer 463, an electroluminescent layer 464, and a second electrode layer 465 are stacked in this order. The source or drain electrode layer 462 is a reflective metal layer, and reflects light emitted from the light emitting element to the upper surface of the arrow. Since the source or drain electrode layer 462 is stacked with the first electrode layer 463, a light-transmitting material is used for the first electrode layer 463 even if light is transmitted. Is reflected by the source or drain electrode layer 462 and radiates to the side opposite to the substrate 460. Needless to say, the first electrode layer 463 may be formed using a reflective metal film. Since light emitted from the light-emitting element is emitted through the second electrode layer 465, the second electrode layer 465 is formed using a light-transmitting material at least in the visible light region.

A case where light is emitted to both sides of the substrate 470 side and the opposite side, that is, a case where both are emitted will be described with reference to FIG. The transistor 471 is also a channel protective thin film transistor. The first electrode layer 472 is electrically connected to the source or drain electrode layer 477 which is electrically connected to the semiconductor layer of the transistor 471. A first electrode layer 472, an electroluminescent layer 473, and a second electrode layer 474 are stacked in this order. At this time, when both the first electrode layer 472 and the second electrode layer 474 are formed with a light-transmitting material at least in a visible region or with a thickness capable of transmitting light, both radiations are realized. In this case, the insulating layer through which light is transmitted and the substrate 470 also need to have a light-transmitting property with respect to light in the visible region.

A mode of a light-emitting element which can be applied to this embodiment mode is shown in FIG. FIG. 15 illustrates an element structure of a light emitting element, in which an electroluminescent layer 860 formed by mixing an organic compound and an inorganic compound is sandwiched between a first electrode layer 870 and a second electrode layer 850. It is. As illustrated, the electroluminescent layer 860 includes a first layer 804, a second layer 803, and a third layer 802.

First, the first layer 804 is a layer that has a function of transporting holes to the second layer 803, and includes a first organic compound and a first organic electron-accepting property with respect to the first organic compound. It is a structure containing an inorganic compound. What is important is not simply that the first organic compound and the first inorganic compound are mixed, but the first inorganic compound exhibits an electron accepting property with respect to the first organic compound. By adopting such a configuration, a large number of hole carriers are generated in the first organic compound which has essentially no inherent carrier, and exhibits extremely excellent hole injection properties and hole transport properties.

Therefore, the first layer 804 has not only effects (such as improved heat resistance) that are considered to be obtained by mixing an inorganic compound, but also excellent conductivity (in particular, in the first layer 804, hole injection). And transportability) can also be obtained. This is an effect that cannot be obtained with a conventional hole transport layer in which an organic compound and an inorganic compound that do not have an electronic interaction with each other are simply mixed. Due to this effect, the drive voltage can be made lower than in the prior art. Further, since the first layer 804 can be thickened without causing an increase in driving voltage, a short circuit of an element due to dust or the like can be suppressed.

By the way, as described above, since hole carriers are generated in the first organic compound, the first organic compound is preferably a hole-transporting organic compound. Examples of the hole-transporting organic compound include phthalocyanine (abbreviation: H ₂ Pc), copper phthalocyanine (abbreviation: CuPc), vanadyl phthalocyanine (abbreviation: VOPc), 4,4 ′, 4 ″ -tris (N, N -Diphenylamino) triphenylamine (abbreviation: TDATA), 4,4 ′, 4 ″ -tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine (abbreviation: MTDATA), 1,3 , 5-tris [N, N-di (m-tolyl) amino] benzene (abbreviation: m-MTDAB), N, N′-diphenyl-N, N′-bis (3-methylphenyl) -1,1 ′ -Biphenyl-4,4'-diamine (abbreviation: TPD), 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (abbreviation: NPB), 4,4'-bis {N -[4-di m-tolyl) amino] phenyl-N-phenylamino} biphenyl (abbreviation: DNTPD), 4,4 ′, 4 ″ -tris (N-carbazolyl) triphenylamine (abbreviation: TCTA), and the like. It is not limited to. Among the compounds described above, aromatic amine compounds typified by TDATA, MTDATA, m-MTDAB, TPD, NPB, DNTPD, TCTA, etc., are prone to generate hole carriers and are suitable as the first organic compound. A group.

On the other hand, the first inorganic compound may be anything as long as it can easily receive electrons from the first organic compound, and various metal oxides or metal nitrides can be used. Any transition metal oxide belonging to Group 12 is preferable because it easily exhibits electron acceptability. Specific examples include titanium oxide, zirconium oxide, vanadium oxide, molybdenum oxide, tungsten oxide, rhenium oxide, ruthenium oxide, and zinc oxide. Among the metal oxides described above, any of the transition metal oxides in Groups 4 to 8 of the periodic table has a high electron accepting property and is a preferred group. Vanadium oxide, molybdenum oxide, tungsten oxide, and rhenium oxide are particularly preferable because they can be vacuum-deposited and are easy to handle.

Note that the first layer 804 may be formed by stacking a plurality of layers to which the above-described combination of an organic compound and an inorganic compound is applied. Moreover, other organic compounds or other inorganic compounds may be further contained.

Next, the third layer 802 will be described. The third layer 802 is a layer having a function of transporting electrons to the second layer 803, and includes at least a third organic compound and a third inorganic compound that exhibits an electron donating property with respect to the third organic compound. It is the structure containing these. What is important is not that the third organic compound and the third inorganic compound are merely mixed, but that the third inorganic compound exhibits an electron donating property with respect to the third organic compound. By adopting such a structure, a large number of electron carriers are generated in the third organic compound which has essentially no inherent carrier, and exhibits extremely excellent electron injecting properties and electron transporting properties.

Therefore, the third layer 802 has not only an effect (such as improvement in heat resistance) considered to be obtained by mixing an inorganic compound but also excellent conductivity (especially in the third layer 802, electron injection). And transportability) can also be obtained. This is an effect that cannot be obtained with a conventional electron transport layer in which an organic compound and an inorganic compound that do not have an electronic interaction with each other are simply mixed. Due to this effect, the drive voltage can be made lower than in the prior art. In addition, since the third layer 802 can be thickened without causing an increase in driving voltage, a short circuit of an element due to dust or the like can be suppressed.

By the way, as described above, since an electron carrier is generated in the third organic compound, the third organic compound is preferably an electron-transporting organic compound. Examples of the electron-transporting organic compound include tris (8-quinolinolato) aluminum (abbreviation: Alq ₃ ), tris (4-methyl-8-quinolinolato) aluminum (abbreviation: Almq ₃ ), bis (10-hydroxybenzo [ h] -quinolinato) beryllium (abbreviation: BeBq ₂ ), bis (2-methyl-8-quinolinolato) (4-phenylphenolato) aluminum (abbreviation: BAlq), bis [2- (2′-hydroxyphenyl) benzoxa Zolato] zinc (abbreviation: Zn (BOX) ₂ ), bis [2- (2′-hydroxyphenyl) benzothiazolate] zinc (abbreviation: Zn (BTZ) ₂ ), bathophenanthroline (abbreviation: BPhen), bathocuproin (abbreviation: BCP), 2- (4-biphenylyl) -5- (4-tert-butylphenyl)- , 3,4-oxadiazole (abbreviation: PBD), 1,3-bis [5- (4-tert-butylphenyl) -1,3,4-oxadiazol-2-yl] benzene (abbreviation: OXD) -7), 2,2 ′, 2 ″-(1,3,5-benzenetriyl) -tris (1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 3- (4-biphenylyl)- 4-phenyl-5- (4-tert-butylphenyl) -1,2,4-triazole (abbreviation: TAZ), 3- (4-biphenylyl) -4- (4-ethylphenyl) -5- (4- tert-butylphenyl) -1,2,4-triazole (abbreviation: p-EtTAZ) and the like, but are not limited thereto. Among the compounds described above, a chelate metal complex having a chelate ligand containing an aromatic ring typified by Alq ₃ , Almq ₃ , BeBq ₂ , BAlq, Zn (BOX) ₂ , Zn (BTZ) ₂ , Organic compounds having a phenanthroline skeleton typified by BPhen, BCP, etc., and organic compounds having an oxadiazole skeleton typified by PBD, OXD-7, etc. are likely to generate electron carriers and are suitable as a third organic compound. Compound group.

On the other hand, the third inorganic compound may be anything as long as it easily gives electrons to the third organic compound, and various metal oxides or metal nitrides can be used. Earth metal oxides, rare earth metal oxides, alkali metal nitrides, alkaline earth metal nitrides, and rare earth metal nitrides are preferable because they easily exhibit electron donating properties. Specific examples include lithium oxide, strontium oxide, barium oxide, erbium oxide, lithium nitride, magnesium nitride, calcium nitride, yttrium nitride, and lanthanum nitride. In particular, lithium oxide, barium oxide, lithium nitride, magnesium nitride, and calcium nitride are preferable because they can be vacuum-deposited and are easy to handle.

Note that the third layer 802 may be formed by stacking a plurality of layers to which the above-described combination of an organic compound and an inorganic compound is applied. Moreover, other organic compounds or other inorganic compounds may be further contained.

Next, the second layer 803 will be described. The second layer 803 is a layer having a light emitting function and includes a light emitting second organic compound. Moreover, the structure containing a 2nd inorganic compound may be sufficient. The second layer 803 can be formed using various light-emitting organic compounds and inorganic compounds. However, since the second layer 803 is less likely to flow current than the first layer 804 and the third layer 802, the thickness is preferably about 10 nm to 100 nm.

The second organic compound is not particularly limited as long as it is a luminescent organic compound. For example, 9,10-di (2-naphthyl) anthracene (abbreviation: DNA), 9,10-di (2 -Naphthyl) -2-tert-butylanthracene (abbreviation: t-BuDNA), 4,4'-bis (2,2-diphenylvinyl) biphenyl (abbreviation: DPVBi), coumarin 30, coumarin 6, coumarin 545, coumarin 545T Perylene, rubrene, periflanthene, 2,5,8,11-tetra (tert-butyl) perylene (abbreviation: TBP), 9,10-diphenylanthracene (abbreviation: DPA), 5,12-diphenyltetracene, 4- ( Dicyanomethylene) -2-methyl- [p- (dimethylamino) styryl] -4H-pyran (abbreviation: DCM1), 4- (di Cyanomethylene) -2-methyl-6- [2- (julolidin-9-yl) ethenyl] -4H-pyran (abbreviation: DCM2), 4- (dicyanomethylene) -2,6-bis [p- (dimethylamino) ) Styryl] -4H-pyran (abbreviation: BisDCM) and the like. In addition, bis [2- (4 ′, 6′-difluorophenyl) pyridinato-N, C ^{2 ′} ] iridium (picolinate) (abbreviation: FIrpic), bis {2- [3 ′, 5′-bis (trifluoromethyl) ) Phenyl] pyridinato-N, C ^{2 ′} } iridium (picolinate) (abbreviation: Ir (CF ₃ ppy) ₂ (pic)), tris (2-phenylpyridinato-N, C ^{2 ′} ) iridium (abbreviation: Ir (Ppy) ₃ ), bis (2-phenylpyridinato-N, C ^{2 ′} ) iridium (acetylacetonate) (abbreviation: Ir (ppy) ₂ (acac)), bis [2- (2′-thienyl) pyridinato -N, C ^{3 ']} iridium (acetylacetonate) _{(abbreviation: Ir (thp) 2 (acac} )), bis (2-phenylquinolinato--N, C ^2') iridium (Asechirua Tonato) _{(abbreviation: Ir (pq) 2 (acac} )), bis [2- (2'-benzothienyl) pyridinato -N, C ^{3 ']} iridium (acetylacetonate) (abbreviation: Ir _(btp) 2 (acac A compound capable of emitting phosphorescence such as)) can also be used.

For the second layer 803, a triplet excitation material containing a metal complex or the like may be used in addition to the singlet excitation light-emitting material. For example, among red light emitting pixels, green light emitting pixels, and blue light emitting pixels, a red light emitting pixel having a relatively short luminance half time is formed of a triplet excitation light emitting material, and the other A singlet excited luminescent material is used. The triplet excited luminescent material has a feature that the light emission efficiency is good, so that less power is required to obtain the same luminance. That is, when applied to a red pixel, the amount of current flowing through the light emitting element can be reduced, so that reliability can be improved. As a reduction in power consumption, a red light-emitting pixel and a green light-emitting pixel may be formed using a triplet excitation light-emitting material, and a blue light-emitting pixel may be formed using a singlet excitation light-emitting material. By forming a green light-emitting element having high human visibility with a triplet excited light-emitting material, power consumption can be further reduced.

Further, in the second layer 803, not only the second organic compound that emits light but also other organic compounds may be added. Examples of the organic compound that can be added include TDATA, MTDATA, m-MTDAB, TPD, NPB, DNTPD, TCTA, Alq ₃ , Almq ₃ , BeBq ₂ , BAlq, Zn (BOX) ₂ , and Zn (BTZ) described above. ₂ , BPhen, BCP, PBD, OXD-7, TPBI, TAZ, p-EtTAZ, DNA, t-BuDNA, DPVBi, etc., 4,4′-bis (N-carbazolyl) biphenyl (abbreviation: CBP), 1 , 3,5-tris [4- (N-carbazolyl) phenyl] benzene (abbreviation: TCPB) can be used, but is not limited thereto. In addition, the organic compound added in addition to the second organic compound in this way has an excitation energy larger than the excitation energy of the second organic compound in order to efficiently emit the second organic compound, and the second organic compound. It is preferable to add more than the organic compound (by this, concentration quenching of the second organic compound can be prevented). Or as another function, you may show light emission with a 2nd organic compound (Thereby, white light emission etc. are also attained).

The second layer 803 may have a structure in which a light emitting layer having a different emission wavelength band is formed for each pixel to perform color display. Typically, a light emitting layer corresponding to each color of R (red), G (green), and B (blue) is formed. In this case as well, it is possible to improve color purity and prevent mirror reflection (reflection) of the pixel portion by providing a filter that transmits light in the emission wavelength band on the light emission side of the pixel. Can do. By providing the filter, it is possible to omit a circularly polarizing plate that has been conventionally required, and it is possible to eliminate the loss of light emitted from the light emitting layer. Furthermore, a change in color tone that occurs when the pixel portion (display screen) is viewed obliquely can be reduced.

The material that can be used for the second layer 803 may be a low molecular weight organic light emitting material or a high molecular weight organic light emitting material. The polymer organic light emitting material has higher physical strength and higher device durability than the low molecular weight material. In addition, since the film can be formed by coating, the device can be manufactured relatively easily.

Since the light emission color is determined by the material for forming the light emitting layer, a light emitting element exhibiting desired light emission can be formed by selecting these materials. Examples of the polymer electroluminescent material that can be used for forming the light emitting layer include polyparaphenylene vinylene, polyparaphenylene, polythiophene, and polyfluorene.

Examples of the polyparaphenylene vinylene include poly (paraphenylene vinylene) [PPV] derivatives, poly (2,5-dialkoxy-1,4-phenylene vinylene) [RO-PPV], poly (2- (2′- Ethyl-hexoxy) -5-methoxy-1,4-phenylenevinylene) [MEH-PPV], poly (2- (dialkoxyphenyl) -1,4-phenylenevinylene) [ROPh-PPV] and the like. Examples of polyparaphenylene include derivatives of polyparaphenylene [PPP], poly (2,5-dialkoxy-1,4-phenylene) [RO-PPP], poly (2,5-dihexoxy-1,4-phenylene). ) And the like. The polythiophene series includes polythiophene [PT] derivatives, poly (3-alkylthiophene) [PAT], poly (3-hexylthiophene) [PHT], poly (3-cyclohexylthiophene) [PCHT], poly (3-cyclohexyl). -4-methylthiophene) [PCHMT], poly (3,4-dicyclohexylthiophene) [PDCHT], poly [3- (4-octylphenyl) -thiophene] [POPT], poly [3- (4-octylphenyl) -2,2 bithiophene] [PTOPT] and the like. Examples of the polyfluorene series include polyfluorene [PF] derivatives, poly (9,9-dialkylfluorene) [PDAF], poly (9,9-dioctylfluorene) [PDOF], and the like.

The second inorganic compound may be any inorganic compound as long as it is difficult to quench the light emission of the second organic compound, and various metal oxides and metal nitrides can be used. In particular, a metal oxide of Group 13 or Group 14 of the periodic table is preferable because it is difficult to quench the light emission of the second organic compound, and specifically, aluminum oxide, gallium oxide, silicon oxide, and germanium oxide are preferable. . However, it is not limited to these.

Note that the second layer 803 may be formed by stacking a plurality of layers to which the above-described combination of an organic compound and an inorganic compound is applied. Moreover, other organic compounds or other inorganic compounds may be further contained. The layer structure of the light-emitting layer can be changed, and instead of having a specific electron injection region or light-emitting region, an electrode layer for this purpose is provided, or a light-emitting material is dispersed. Modifications can be made without departing from the spirit of the present invention.

A light-emitting element formed using the above materials emits light by being forward-biased. A pixel of a display device formed using a light-emitting element can be driven by a simple matrix method or an active matrix method. In any case, each pixel emits light by applying a forward bias at a specific timing, but is in a non-light emitting state for a certain period. By applying a reverse bias during this non-light emitting time, the reliability of the light emitting element can be improved. The light emitting element has a degradation mode in which the light emission intensity decreases under a constant driving condition and a degradation mode in which the non-light emitting area is enlarged in the pixel and the luminance is apparently decreased. However, alternating current that applies a bias in the forward and reverse directions. By performing a typical drive, the progress of deterioration can be delayed, and the reliability of the light-emitting display device can be improved. Further, either digital driving or analog driving can be applied.

Therefore, a color filter (colored layer) may be formed on the sealing substrate. The color filter (colored layer) can be formed by an evaporation method or a droplet discharge method. When the color filter (colored layer) is used, high-definition display can be performed. This is because the color filter (colored layer) can be corrected so that a broad peak becomes a sharp peak in the emission spectrum of each RGB. In addition to full color display using three types of R, G, and B pixels, three-color video data is converted into four-color video data, and four types of R, G, B, and W (white) pixels are converted. The full color display used may be used. When four types of pixels are used, the luminance increases and a lively video display can be performed.

Full color display can be performed by forming a material exhibiting monochromatic light emission and combining a color filter and a color conversion layer. The color filter (colored layer) and the color conversion layer may be formed, for example, on the second substrate (sealing substrate) and attached to the substrate.

Of course, monochromatic light emission may be displayed. For example, an area color type display device may be formed using monochromatic light emission. As the area color type, a passive matrix type display unit is suitable, and characters and symbols can be mainly displayed.

The materials of the first electrode layer 870 and the second electrode layer 850 need to be selected in consideration of the work function, and both the first electrode layer 870 and the second electrode layer 850 are anodes depending on the pixel structure. Or a cathode. In the case where the polarity of the driving thin film transistor is a p-channel type, the first electrode layer 870 may be an anode and the second electrode layer 850 may be a cathode as illustrated in FIG. In the case where the polarity of the driving thin film transistor is an n-channel type, it is preferable that the first electrode layer 870 be a cathode and the second electrode layer 850 be an anode as shown in FIG. Materials that can be used for the first electrode layer 870 and the second electrode layer 850 are described. In the case where the first electrode layer 870 and the second electrode layer 850 function as anodes, a material having a high work function (specifically, a material of 4.5 eV or more) is preferable, and the first electrode layer 870 and the second electrode layer 870 In the case where the electrode layer 850 functions as a cathode, a material having a low work function (specifically, a material of 3.5 eV or less) is preferable. However, since the hole injection characteristics and hole transport characteristics of the first layer 804 and the electron injection characteristics and electron transport characteristics of the third layer 802 are excellent, both the first electrode layer 870 and the second electrode layer 850 are used. Various materials can be used with almost no work function limitation.

15A and 15B has a structure in which light is extracted from the first electrode layer 870, the second electrode layer 850 does not necessarily have a light-transmitting property. The second electrode layer _{850, Ti, TiN, TiSi X} N Y, Ni, W, WSi X, WN X, WSi X N Y, NbN, Cr, Pt, Zn, Sn, In, Ta, Al, Cu , An element selected from Au, Ag, Mg, Ca, Li, or Mo, or a film mainly composed of an alloy material or a compound material containing the element as a main component or a laminated film thereof having a total film thickness of 100 nm to 800 nm Use within a range.

The second electrode layer 850 can be formed by an evaporation method, a sputtering method, a CVD method, a printing method, a droplet discharge method, or the like.

In addition, when a light-transmitting conductive material such as a material used for the first electrode layer 870 is used for the second electrode layer 850, light is extracted from the second electrode layer 850, so that the light-emitting element can emit light. The emitted light can be a dual emission structure that is emitted from both the first electrode layer 870 and the second electrode layer 850.

Note that the light-emitting element of the present invention has various variations by changing types of the first electrode layer 870 and the second electrode layer 850.

FIG. 15B illustrates a case where the electroluminescent layer 860 is formed in order of the third layer 802, the second layer 803, and the first layer 804 from the first electrode layer 870 side.

As described above, in the light-emitting element of the present invention, the electric field in which the layer sandwiched between the first electrode layer 870 and the second electrode layer 850 includes a layer in which an organic compound and an inorganic compound are combined is included. The light emitting layer 860 is formed. Then, by mixing the organic compound and the inorganic compound, there are provided layers (that is, the first layer 804 and the third layer 802) that can obtain functions of high carrier injection and carrier transport that cannot be obtained independently. This is an organic / inorganic composite light emitting element. In addition, the first layer 804 and the third layer 802 are effective when the organic compound and the inorganic compound are combined, but only the organic compound and the inorganic compound may be used.

Note that although the electroluminescent layer 860 includes a layer in which an organic compound and an inorganic compound are mixed, various methods can be used as a method for forming the layer. A co-evaporation method in which both an organic compound and an inorganic compound are simultaneously deposited can be used. For example, there is a technique in which both an organic compound and an inorganic compound are evaporated by resistance heating and co-evaporated. In addition, while the organic compound is evaporated by resistance heating, the inorganic compound may be evaporated by electron beam (EB) and co-evaporated. Further, there is a method of evaporating the organic compound by resistance heating and simultaneously sputtering the inorganic compound and depositing both at the same time. In addition, the film may be formed by a wet method.

Similarly, for the first electrode layer 870 and the second electrode layer 850, a vapor deposition method using resistance heating, an EB vapor deposition method, a sputtering method, a wet method, or the like can be used.

FIG. 15C shows a structure in which a reflective electrode layer is used for the first electrode layer 870 and a light-transmitting electrode layer is used for the second electrode layer 850 in FIG. 15A. Light emitted from the element is reflected by the first electrode layer 870 and transmitted through the second electrode layer 850 to be emitted. Similarly, in FIG. 15D, a reflective electrode layer is used for the first electrode layer 870 and a light-transmitting electrode layer is used for the second electrode layer 850 in FIG. 15B. The light emitted from the light emitting element is reflected by the first electrode layer 870 and is transmitted through the second electrode layer 850 and emitted. This embodiment mode can be freely combined with each of Embodiment Modes 1 to 18.

(Embodiment 20)
Next, a mode in which a driver circuit for driving is mounted on the display device of the present invention will be described.

First, a display device employing a COG method is described with reference to FIG. A pixel portion 2701 for displaying information such as characters and images is provided over the substrate 2700. A substrate provided with a plurality of drive circuits is divided into a rectangular shape, and a divided drive circuit (also referred to as a driver IC) 2751 is mounted on the substrate 2700. FIG. 18A illustrates a mode in which an FPC 2750 is mounted on the tip of a plurality of driver ICs 2751 and driver ICs 2751. Further, the size to be divided may be substantially the same as the length of the side of the pixel portion on the signal line side, and a tape may be mounted on the tip of the driver IC on a single driver IC.

Alternatively, a TAB method may be employed. In that case, a plurality of tapes may be attached and driver ICs may be mounted on the tapes as shown in FIG. As in the case of the COG method, a single driver IC may be mounted on a single tape. In this case, a metal piece or the like for fixing the driver IC may be attached together due to strength problems.

A plurality of driver ICs mounted on these display panels may be formed on a rectangular substrate having a side of 300 mm to 1000 mm or more from the viewpoint of improving productivity.

That is, a plurality of circuit patterns having a drive circuit portion and an input / output terminal as one unit may be formed on the substrate, and finally divided and taken out. The long side of the driver IC may be formed in a rectangular shape having a long side of 15 to 80 mm and a short side of 1 to 6 mm in consideration of the length of one side of the pixel portion and the pixel pitch. Or a length obtained by adding one side of the pixel portion and one side of each driver circuit.

The advantage of the external dimensions of the driver IC over the IC chip lies in the length of the long side. When a driver IC formed with a long side of 15 to 80 mm is used, the number required for mounting corresponding to the pixel portion is as follows. This is less than when an IC chip is used, and the manufacturing yield can be improved. Further, when a driver IC is formed over a glass substrate, the shape of the substrate used as a base is not limited, and thus productivity is not impaired. This is a great advantage compared with the case where the IC chip is taken out from the circular silicon wafer.

In the case where the scan line driver circuit 3702 is formed over the substrate as shown in FIG. 17B, a driver IC in which a driver circuit driver circuit on the signal line side is formed in a region outside the pixel portion 3701. Is implemented. These driver ICs are drive circuits on the signal line side. In order to form a pixel region corresponding to RGB full color, the number of signal lines in the XGA class is 3072 and the number in the UXGA class is 4800. The signal lines formed in such a number are divided into several blocks at the end of the pixel portion 3701 to form lead lines, and are collected according to the pitch of the output terminals of the driver IC. The driver IC can be formed of a crystalline semiconductor formed on a substrate.

As shown in FIGS. 18A and 18B, driver ICs may be mounted as both the scanning line driver circuit and the signal line driver circuit. In that case, the specifications of the driver ICs used on the scanning line side and the signal line side may be different. For example, although a transistor constituting the driver IC on the scanning line side is required to have a withstand voltage of about 30 V, the driving frequency is 100 kHz or less, and a relatively high speed operation is not required. Therefore, it is preferable to set the channel length (L) of the transistors forming the driver on the scanning line side to be sufficiently large. On the other hand, it is sufficient for the transistor of the driver IC on the signal line side to have a withstand voltage of about 12V, but the drive frequency is about 65 MHz at 3V, and high speed operation is required. Therefore, it is preferable to set the channel length and the like of the transistors constituting the driver on the micron rule.

By setting the thickness of the driver IC to be the same as that of the counter substrate, the height between the two becomes substantially the same, which contributes to the reduction in thickness of the entire display device. In addition, since each substrate is made of the same material, thermal stress is not generated even when a temperature change occurs in the display device, and the characteristics of a circuit made of TFTs are not impaired. In addition, the number of driver ICs to be mounted in one pixel region can be reduced by mounting the drive circuit with a driver IC that is longer than the IC chip as shown in this embodiment.

As described above, a driver circuit can be incorporated in the display panel.

(Embodiment 21)
An example of a protection circuit included in the display device of the present invention will be described.

As shown in FIG. 18, a protection circuit 2713 can be formed between the external circuit and the internal circuit. The protection circuit is composed of one or a plurality of elements selected from a TFT, a diode, a resistance element, a capacitance element, and the like, and the configurations and operations of some protection circuits will be described below. First, a configuration of an equivalent circuit diagram of a protection circuit arranged between an external circuit and an internal circuit and corresponding to one input terminal will be described with reference to FIG. The protection circuit illustrated in FIG. 19A includes p-channel thin film transistors 7220 and 7230, capacitor elements 7210 and 7240, and a resistance element 7250. The resistance element 7250 is a two-terminal resistor, and an input voltage Vin (hereinafter referred to as Vin) is applied to one end, and a low potential voltage VSS (hereinafter referred to as VSS) is applied to the other end.

The protection circuit shown in FIG. 19B is an equivalent circuit diagram in which p-channel thin film transistors 7220 and 7230 are substituted with rectifying diodes 7260 and 7270. The protection circuit shown in FIG. 19C is an equivalent circuit diagram in which the p-channel thin film transistors 7220 and 7230 are substituted with TFTs 7350, 7360, 7370, and 7380. Further, as a protection circuit having a structure different from the above, the protection circuit illustrated in FIG. 19D includes resistors 7280 and 7290 and an n-channel thin film transistor 7300. A protection circuit illustrated in FIG. 19E includes resistors 7280 and 7290, a p-channel thin film transistor 7310, and an n-channel thin film transistor 7320. Providing the protective circuit prevents abrupt fluctuations in potential and can prevent element destruction or damage, improving reliability. Note that the element forming the protection circuit is preferably formed using an amorphous semiconductor with excellent withstand voltage. This embodiment mode can be freely combined with the above embodiment modes.

(Embodiment 22)
A television device can be completed with the display device formed according to the present invention. FIG. 20 is a block diagram illustrating a main configuration of the television device. In the display panel, only the pixel portion 601 is formed as shown in FIG. 17A, and the scan line side driver circuit 603 and the signal line side driver circuit 602 have a TAB method as shown in FIG. TFTs are formed as shown in FIG. 17B, and the pixel portion 601 and the scan line side driver circuit 603 are mounted on the substrate. In the case where the signal line side driver circuit 602 is formed as a separate driver IC and formed integrally therewith, as shown in FIG. 17C, the pixel portion 601, the signal line side driver circuit 602, and the scanning line side driver circuit 603 are mounted on the substrate. However, any form is possible.

As other external circuit configurations, on the input side of the video signal, among the signals received by the tuner 604, the video signal amplifier circuit 605 that amplifies the video signal, and the signals output from the video signal amplifier circuit 605 are red, green, and blue colors. And a control circuit 607 for converting the video signal into the input specification of the driver IC. The control circuit 607 outputs signals to the scanning line side and the signal line side, respectively. In the case of digital driving, a signal dividing circuit 608 may be provided on the signal line side and an input digital signal may be divided into m pieces and supplied.

Of the signals received by the tuner 604, the audio signal is sent to the audio signal amplification circuit 609, and the output is supplied to the speaker 613 through the audio signal processing circuit 610. The control circuit 611 receives the receiving station (reception frequency) and volume control information from the input unit 612 and sends a signal to the tuner 604 and the audio signal processing circuit 610.

As shown in FIGS. 21A and 21B, the display module can be incorporated into a housing to complete the television device. The display panel as shown in FIG. 1 attached up to the FPC is generally also referred to as an EL display module. Therefore, when an EL display module as shown in FIG. 1 is used, an EL television device can be completed. A main screen 2003 is formed by the display module, and a speaker portion 2009, operation switches, and the like are provided as other accessory equipment. Thus, a television device can be completed according to the present invention.

Moreover, you may make it cut off the reflected light of the light which injects from the outside using a phase difference plate or a polarizing plate. In the case of a top emission display device, an insulating layer serving as a partition may be colored and used as a black matrix. This partition wall can also be formed by a droplet discharge method or the like. Carbon black or the like may be mixed with a pigment-based black resin or a resin material such as polyimide, or may be laminated. A different material may be discharged to the same region a plurality of times by a droplet discharge method to form a partition wall. As the phase difference plate, a λ / 4 plate and a λ / 2 plate may be used and designed so as to control light. The structure is a light emitting element, a sealing substrate (sealing material), a retardation plate (λ / 4, λ / 2), and a polarizing plate in order from the TFT element substrate side, and light emitted from the light emitting element. Passes through these and is emitted to the outside from the polarizing plate side. The retardation plate and the polarizing plate may be installed on the side from which light is emitted, and may be installed on both sides as long as the display is a double-sided emission type that emits light on both sides. Further, an antireflection film may be provided outside the polarizing plate. This makes it possible to display a higher-definition and precise image.

As shown in FIG. 21A, a display panel 2002 using a display element is incorporated in a housing 2001, and the receiver 2005 starts receiving general television broadcasts, and is wired or wirelessly via a modem 2004. By connecting to a communication network, information communication in one direction (from the sender to the receiver) or in both directions (between the sender and the receiver or between the receivers) can be performed. The television device can be operated by a switch incorporated in the housing or a separate remote controller 2006, and this remote controller is also provided with a display unit 2007 for displaying information to be output. Also good.

In addition, the television device may have a configuration in which a sub screen 2008 is formed using the second display panel in addition to the main screen 2003 to display channels, volume, and the like. In this configuration, the main screen 2003 may be formed using an EL display panel with an excellent viewing angle, and the sub screen 2008 may be formed using a liquid crystal display panel that can display with low power consumption. In order to give priority to low power consumption, the main screen 2003 may be formed using a liquid crystal display panel, the sub screen 2008 may be formed using an EL display panel, and the sub screen 2008 may be blinkable. Of course, both the main screen and the sub screen may be formed by an EL display panel to which the present invention is applied. By using the present invention, a highly reliable display device can be obtained.

FIG. 21B illustrates a television device having a large display portion of 20 to 80 inches, for example, which includes a housing 2010, a display portion 2011, a remote control device 2012 that is an operation portion, a speaker portion 2013, and the like. The present invention is applied to manufacture of the display portion 2011. The television device in FIG. 21B is a wall-hanging type and does not require a large installation space.

Of course, the present invention is not limited to a television device, but can be applied to various uses as a display medium for large areas such as personal computer monitors, information display boards at railway stations and airports, and advertisement display boards on streets. can do.

A television device to which the present invention is applied can have high performance and high reliability. In addition, because it can be manufactured at low cost, it can be used in outdoor environments such as information display panels at railway stations and airports, and advertisement display panels in the street, where wear and deterioration are fast, and frequent replacement is required. In some cases, it can be purchased at a low price.

When the present invention is used, the number of wirings in a pixel can be simplified, so that an aperture ratio can be improved and a manufacturing process is also simplified. Therefore, such a highly reliable display device can be manufactured with high yield.

(Embodiment 23)
Various display devices can be manufactured by applying the present invention. That is, the present invention can be applied to various electronic devices in which these display devices are incorporated in a display portion.

Such electronic devices include cameras such as video cameras and digital cameras, projectors, head mounted displays (goggles type displays), car navigation systems, car stereos, personal computers, game machines, personal digital assistants (mobile computers, mobile phones or And an image reproducing apparatus (specifically, an apparatus having a display capable of reproducing a recording medium such as Digital Versatile Disc (DVD) and displaying the image). Examples thereof are shown in FIG.

The present invention can be used for the display portion of the electronic device shown in FIGS. A display portion can be formed using the display device described in any of Embodiments 1 to 21. As described in the above embodiment mode, when the present invention is applied, a display portion can be formed with low yield and high yield. In addition, the manufactured electronic device can have high performance and high reliability.

FIG. 24A illustrates a personal computer, which includes a main body 2101, a housing 2102, a display portion 2103, a keyboard 2104, an external connection port 2105, a pointing mouse 2106, and the like. The present invention can be applied to manufacture of the display portion 2103, and high performance and high reliability can be achieved. Further, since a high aperture ratio can be obtained in the display portion, a clear and bright display can be enjoyed even when the display portion is mounted on a display portion of a small electronic device.

FIG. 24B shows an image reproduction device (specifically, a DVD reproduction device) provided with a recording medium, which includes a main body 2201, a housing 2202, a display portion A 2203, a display portion B 2204, and a recording medium (DVD etc.) reading portion 2205. , An operation key 2206, a speaker portion 2207, and the like. The display portion A 2203 mainly displays image information, and the display portion B 2204 mainly displays character information. However, the present invention can be applied to the production of the display portion A 2203 and the display portion B 2204, and has high performance and high reliability. Is possible. Further, since a high aperture ratio can be obtained in the display portion, a clear and bright display can be enjoyed even when the display portion is mounted on a display portion of a small electronic device.

FIG. 24C illustrates a mobile phone, which includes a main body 2301, an audio output portion 2302, an audio input portion 2303, a display portion 2304, operation switches 2305, an antenna 2306, and the like. By applying the display device manufactured according to the present invention to the display portion 2304, high performance and high reliability can be achieved. Further, since a high aperture ratio can be obtained in the display portion, a clear and bright display can be enjoyed even when the display portion is mounted on a display portion of a small electronic device.

FIG. 24D shows a video camera, which includes a main body 2401, a display portion 2402, a housing 2403, an external connection port 2404, a remote control receiving portion 2405, an image receiving portion 2406, a battery 2407, an audio input portion 2408, operation keys 2409, and the like. . The present invention can be applied to the display portion 2402. By applying the display device manufactured according to the present invention to the display portion 2402, high performance and high reliability can be achieved. Further, since a high aperture ratio can be obtained in the display portion, a clear and bright display can be enjoyed even when the display portion is mounted on a display portion of a small electronic device.

FIG. 24E illustrates a digital player, which includes a main body 2501, a display portion 2502, operation keys 2503, a recording medium 2504, an earphone 2506 that is a small device for converting an electrical signal into an acoustic signal, and the like. The digital player shown in FIG. 24E has a function of recording and reproducing audio (music) and video, and the recording medium 2504 uses a flash memory and has a capacity of 20 to 200 gigabytes. The present invention can be applied to the display portion 2502. By applying the display device manufactured according to the present invention to the display portion 2304, high performance and high reliability can be achieved. Further, since a high aperture ratio can be obtained in the display portion, a clear and bright display can be enjoyed even when the display portion is mounted on a display portion of a small electronic device.

(Embodiment 24)
An example in which the display device described in any of the above embodiments is applied to a flexible display device as this embodiment will be described with reference to FIGS.

The display device of the present invention illustrated in FIG. 22 may be included in a housing, and includes a main body 660, a pixel portion 661 for displaying an image, a driver IC 662, a receiving device 663, a film battery 664, and the like. The driver IC and the receiving device may be mounted using semiconductor parts. In the display device of the present invention, a material constituting the main body 660 is formed of a flexible material such as a plastic or a film.

Such a display device of the present invention is a display device with a high aperture ratio, can be manufactured with high yield, and can improve reliability.

In addition, since such a display device is very light and flexible, it can be rolled into a cylindrical shape, and is a display device that is very advantageous to carry. The display device of the present invention can freely carry a large-screen display medium.

Note that the display device shown in FIG. 22 includes a navigation system, a sound reproduction device (car audio, audio component, etc.), a personal computer, a game machine, a portable information terminal (mobile computer, mobile phone, portable game machine, electronic book, etc.) ), Home appliances such as refrigerators, washing machines, rice cookers, landline telephones, vacuum cleaners, thermometers, etc., to large-area information displays such as hanging advertisements in trains, and information on arrival and departure of train stations and airports. It can be used mainly as a means for displaying still images.

As described above, the preferred embodiments of the present invention have been particularly shown. However, it is easy for those skilled in the art to modify the embodiments and details in various ways without departing from the spirit and scope of the present invention. To be understood.

The conceptual diagram which shows this invention. FIG. 10 is a circuit diagram illustrating a structure of a pixel that can be applied to the display device of the present invention. Sectional drawing which shows the display apparatus of this invention. FIG. 10 is a circuit diagram illustrating a structure of a pixel that can be applied to the display device of the present invention. FIG. 10 is a circuit diagram illustrating a structure of a pixel that can be applied to the display device of the present invention. FIG. 10 is a circuit diagram illustrating a structure of a pixel that can be applied to the display device of the present invention. FIG. 10 is a circuit diagram illustrating a structure of a pixel that can be applied to the display device of the present invention. FIG. 10 is a circuit diagram illustrating a structure of a pixel that can be applied to the display device of the present invention. FIG. 10 is a circuit diagram illustrating a structure of a pixel that can be applied to the display device of the present invention. FIG. 10 is a circuit diagram illustrating a structure of a pixel that can be applied to the display device of the present invention. FIG. 10 is a circuit diagram illustrating a structure of a pixel that can be applied to the display device of the present invention. Sectional drawing which shows the display apparatus of this invention. FIG. 6 illustrates a display device of the present invention. Sectional drawing which shows the display apparatus of this invention. FIG. 6 illustrates a structure of a light-emitting element that can be applied to the present invention. Sectional drawing which shows the display apparatus of this invention. The top view of the display apparatus of this invention. The top view of the display apparatus of this invention. The figure which shows the protection circuit to which this invention is applied. 1 is a block diagram illustrating a main configuration of an electronic device to which the present invention is applied. FIG. 11 illustrates an electronic device to which the present invention is applied. FIG. 11 illustrates an electronic device to which the present invention is applied. Sectional drawing which shows the display apparatus of this invention. FIG. 11 illustrates an electronic device to which the present invention is applied. FIG. 10 is a circuit diagram illustrating a structure of a pixel that can be applied to the display device of the present invention. The conceptual diagram which shows this invention. The conceptual diagram which shows this invention. The conceptual diagram which shows this invention. Sectional drawing which shows the display apparatus of this invention. FIG. 6 is a top view illustrating a display device of the present invention. FIG. 6 is a top view illustrating a display device of the present invention. FIG. 6 is a top view illustrating a display device of the present invention.

Claims (10)

A correction circuit, a light emitting element, a switch, and a transistor;
One terminal of the switch is electrically connected to the correction circuit;
The gate of the transistor is electrically connected to the correction circuit, one of the source and drain of the transistor is electrically connected to the first electrode of the light emitting element, and the other of the source and drain of the transistor is constant. Kept at a potential,
The display device, wherein the second electrode of the light emitting element and the other terminal of the switch are electrically connected to the same wiring. The display device according to claim 1, wherein the switch is a transistor. A correction circuit, a light emitting element, a first switch, a second switch, a transistor, and a control circuit;
One terminal of the control circuit is kept at a constant potential;
One terminal of the first switch is electrically connected to the correction circuit;
One terminal of the second switch is electrically connected to the correction circuit, and the other terminal of the second switch is electrically connected to the first wiring;
The gate of the transistor is electrically connected to the correction circuit, one of the source and drain of the transistor is electrically connected to the first electrode of the light emitting element, and the other of the source and drain of the transistor is the control Electrically connected to the other terminal of the circuit,
The display device, wherein the second electrode of the light emitting element and the other terminal of the first switch are electrically connected to the same second wiring. A light emitting element, a first switch, a second switch, a transistor, a first capacitor element, and a second capacitor element;
One terminal of the first switch is electrically connected to the first electrode of the second capacitor;
A second electrode of the second capacitor element is electrically connected to one terminal of the second switch and the first electrode of the first capacitor element;
The second electrode of the first capacitive element is kept at a constant potential;
A gate of the transistor is electrically connected to a first electrode of the second capacitor; one of a source and a drain of the transistor is electrically connected to a first electrode of the light-emitting element; The other of the source and the drain is electrically connected to the other terminal of the second switch and kept at a constant potential;
The display device, wherein the second electrode of the light emitting element and the other terminal of the first switch are electrically connected to the same wiring. 5. The display device according to claim 3, wherein the first switch and the second switch are transistors. A light emitting element, a first switch, a second switch, a third switch, a fourth switch, a transistor, a first capacitor element, and a second capacitor element;
One terminal of the fourth switch is kept at a constant potential;
One terminal of the first switch is electrically connected to the first electrode of the second capacitor;
A second electrode of the second capacitor element is electrically connected to one terminal of the second switch and the first electrode of the first capacitor element;
The second electrode of the first capacitive element is kept at a constant potential;
One terminal of the third switch is electrically connected to the second electrode of the second capacitor, and the other terminal of the third switch is electrically connected to the first wiring;
A gate of the transistor is electrically connected to a first electrode of the second capacitor; one of a source and a drain of the transistor is electrically connected to a first electrode of the light-emitting element; The other of the source and the drain is electrically connected to the other terminal of the second switch and the other terminal of the fourth switch;
The display device, wherein the second electrode of the light emitting element and the other terminal of the first switch are electrically connected to the same second wiring. The display device according to claim 6, wherein the first switch, the second switch, the third switch, and the fourth switch are transistors. The display device according to claim 1, wherein the wiring is maintained at a constant potential. 7. The display device according to claim 3, wherein the second wiring is maintained at a constant potential. The display device according to claim 1, wherein the transistor is a thin film transistor.

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