JP2002299051A - Semiconductor device and manufacturing mask for semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformize the film thickness of a light-emitting layer, and to increase the strength of a light-emitting layer forming mask in an organic EL display. SOLUTION: An anode 61 and a common cathode are formed with respective pixels of the organic EL display. An electric current is carried between the anode 61 and the cathode, by being switched by thin-film transistors 13 and 42 and auxiliary capacity 70, to make an organic EL element emit light. The organic EL element is composed of a hole transport layer, an organic light- emitting layer, and an electron transport layer. The organic light-emitting layer is used in common to adjacent two identical pixels 1a and 1b. The anodes 61 of the adjacent two pixels 1a and 1b are arranged mutually opposite in close vicinity to each other to that a switching element is not interposed between these anodes. The organic light-emitting layer is used in common to prevent reduction in the film thickness of the organic light-emitting layer in an end part of a shadow mask at vapor deposition time so that the film thickness of the organic light-emitting layer on the anode 61 can be uniformized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device and a mask for manufacturing a semiconductor device, and more particularly to an increase in an effective light emitting area.

[0002]

2. Description of the Related Art Hitherto, a display panel using an organic electroluminescence (organic EL) element has been known as a flat display panel. The organic EL element is a natural light display that emits light from the organic EL layer by supplying a current to the organic EL layer provided between the anode and the cathode, and does not require a backlight like an LCD. It is expected as the mainstream of flat display panels. In particular, in an active matrix type organic EL display in which a switching element is formed in each pixel, a large screen can be obtained because display data can be held for each pixel.
High definition is possible and is promising.

In such an organic EL display, an organic EL layer as a light emitting layer is generally formed on a circuit board by a vapor deposition method using a shadow mask.

FIG. 9 schematically shows a pixel arrangement of a conventional color organic EL display 1. The organic EL display 1 includes a plurality of pixels 1a arranged in a matrix. Each pixel 1a has a switching element such as a thin film transistor, and the switching element of each pixel is driven by a gate line corresponding to a row and a data line corresponding to a column to cause the organic EL element to emit light. The arrangement of the R, G, and B pixels is arbitrary. For example, as shown in the figure, the R, G, and B pixels can be arranged linearly (in a row) (stripe arrangement).

FIG. 10 is a detailed plan view of the pixel 1a in FIG. 9, and FIGS. 11 (a) and 11 (b)
AA section and BB section in FIG. 10 are shown. In both figures, a region surrounded by a gate line 51 extending in a row direction and a data line 52 extending in a column direction is one pixel region 1a, in which an n-channel thin film transistor 13, an auxiliary capacitor 70, and a p-channel thin film transistor 42 Are formed, and an organic EL element 65 connected to the drain of the thin film transistor 42 via the drain electrode 43d is provided. The source of the thin film transistor 42 is connected to a power supply line 53 via a source electrode 43s.

The active layer 9 of the thin film transistor 13 has a double-gate structure in which the active layer 9 passes through the gate electrode 11 projecting from the gate line 51 twice. The drain of the thin film transistor 13 is the drain electrode 1
6 is connected to the data line 52, and the source is the thin film transistor 4 via the auxiliary capacitor 70 and the bridge structure.
2 gate 41. The auxiliary capacitor 70 is connected to the power supply V
It is composed of an SC line 54 connected to SC and an electrode 55 integrated with the active layer 9.

As described above, the drain of the thin film transistor 42 is connected to the organic EL element 60. The organic EL element 60 includes an anode (transparent electrode) 61 formed for each pixel on the flattening insulating film 17 on the thin film transistors 13 and 42;
A cathode (metal electrode) 66 formed on the uppermost layer in common for each pixel
And the organic layer 6 laminated between the anode 61 and the cathode 66
5 is comprised. The anode 61 is made of ITO or the like, and has a drain and a drain electrode 4 of the thin film transistor 42.
Connected via 3d. In addition, the organic layer 65 is
The hole transport layer 62, the organic light emitting layer 63, and the electron transport layer 64 are sequentially laminated from the first side. The organic light emitting layer 63
Although the material is different for each of the R pixel, the G pixel, and the B pixel, the material includes, for example, BeBq2 containing a quinacridone derivative.

Note that all the components of each pixel described above are formed on the substrate 3 in a laminated manner. That is, the insulating layer 4 is formed on the substrate 3, and the semiconductor layer 9 is pattern-formed thereon. Gates 11 and 41 are formed on semiconductor layer 9 with gate oxide film 12 interposed therebetween. An interlayer insulating film 15 is formed on gates 11 and 41, and anode 61 and active layer 9 made of polycrystalline silicon or the like are connected through a contact hole formed in interlayer insulating film 15.

Further, in order to form the organic EL element 60 on the transparent anode 61 formed for each pixel, as shown in FIG. 12, a shadow mask 2 having an opening 2a corresponding to each pixel must be The organic light-emitting layer 63 may be deposited for each pixel, G pixel, and B pixel. Since current is mainly supplied to a region sandwiched between the anode 61 and the cathode 66,
The organic light emitting layer 63 is formed by being positioned on the anode 61.

In such a configuration, the gate line 5
When the selection signal is output to 1, the thin film transistor 13 is turned on, and the auxiliary capacitance 70 is charged according to the voltage value of the data signal applied to the data line 52 at that time.
The gate of the thin-film transistor 42 receives a voltage corresponding to the charge charged in the capacitor 70, the current supplied from the power supply line 53 to the organic EL element is controlled, and the element emits light with a luminance corresponding to the supplied current. .

[0011]

As described above, in order to form the organic light emitting layer 63 for each pixel in the related art, FIG.
2, a mask 2 having an opening 2a corresponding to each pixel is used, and the distance between the openings 2a, that is, the non-opening distance d is small and the strength of the mask 2 is small. There was a problem.

Further, due to shadowing occurring at the end of the opening 2a, the film thickness of the organic light emitting layer 63 formed becomes small at the end of the opening 2a, and the film thickness becomes non-uniform. There has been a problem that deterioration and a decrease in the effective light emitting area are caused.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to increase the strength of a mask for forming a light emitting layer, and to increase the effective light emitting area by eliminating uneven light emission. It is an object of the present invention to provide an apparatus and a mask that can be used.

[0014]

In order to achieve the above object, the present invention comprises a plurality of pixels having a light emitting layer provided between a first electrode and a second electrode. In the semiconductor device, the first electrode is provided for each of the pixels, and the light-emitting layer is formed of two adjacent pixels among the plurality of pixels.
One pixel is shared, and the first electrodes of the two adjacent pixels are arranged on the side of another adjacent pixel in the pixel.

According to another aspect of the present invention, there is provided a pixel having a first electrode and a second electrode, a switching element connected to the first electrode, and a light emitting layer provided between the first electrode and the second electrode. A semiconductor device configured by arranging a plurality of
The light emitting layer is shared by two adjacent pixels among a plurality of the pixels, and the first electrodes of the two adjacent pixels are opposed to each other at a plane position without the switching element interposed therebetween. It is characterized by the following.

Here, it is preferable that the switching elements of the two adjacent pixels are respectively arranged at both ends of the first electrode so as to sandwich the first electrode which is opposed to each other in a plane position. is there.

Further, the first of the two adjacent pixels is
The electrodes and the switching elements can be arranged symmetrically with respect to the axis of the opposed arrangement.

Further, the first electrodes can be arranged point-symmetrically with respect to a center axis of the opposed arrangement.

In this device, it is preferable that the two adjacent pixels have the same color. In this case, the pixels of the same color can be arranged adjacently in a column, and the light emitting layer can be shared between two adjacent pixels in the column. Also,
The pixels of the same color may be arranged in a zigzag pattern, and the light emitting layer may be shared between two adjacent pixels in the zigzag pattern. The pixel of the same color can be at least one of an R pixel, a G pixel, and a B pixel.

In this device, the light emitting layer is an organic EL.
And an organic EL display.

As described above, in the present invention, the light emitting layer is shared between two adjacent pixels. At this time, since the anodes of two adjacent pixels are arranged close to each other and opposed to each other, the interval between openings of a mask for forming a light emitting layer can be increased, thereby increasing the mask strength. In addition, by sharing the light emitting layer between two adjacent pixels, the number of openings is reduced, and a decrease in the film thickness of the light emitting layer due to shadowing generated at the end of the opening is suppressed to make the film thickness uniform. be able to.

Further, the present invention provides the light emitting layer forming mask for manufacturing the above semiconductor device. The mask has an opening common to the two adjacent pixels, and the material of the light emitting layer is passed through the opening to form the light emitting layer.

With the mask of the present invention, the number of openings can be reduced, shadowing can be suppressed, and the light emitting layer can be formed more uniformly than before. Further, by sharing the opening between two adjacent pixels, the length between the openings can be secured, and the mask strength can be increased.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings, taking an organic EL display as an example.

FIG. 1 shows an organic light emitting layer 6 according to this embodiment.
The shadow mask 2 for forming 3 is shown. In the related art, a discrete opening 2a is provided for each pixel, but in the present embodiment, an opening 2a common to two adjacent pixels is provided. Specifically, when focusing on a certain color, for example, an R pixel, the R pixel group is arranged on a straight line in the column direction, and the opening 2a for forming the R pixel is also arranged on a straight line in the column direction. Therefore, by making the opening 2a common between two adjacent pixels, an elongated opening 2a as shown in the figure is eventually obtained. The width of the opening 2a is the same as that of the related art, and the length is about twice that of the related art. Opening 2
The interval D of a, that is, the length D of the non-opening portion is larger than the conventional length d between the opening portions. This will be further described later. The pitch of the openings 2a is equal to the same color pixel pitch in the row direction. The thickness of the mask 2 is set to 50
It can be about μm. The same applies to the mask for G pixels or the mask for B pixels.

An organic EL material is deposited using such a mask 2 to form an organic light emitting layer 63 for the R pixel, an organic light emitting layer 63 for the G pixel, and an organic light emitting layer 63 for the B pixel. .

FIG. 2 is a plan view of an organic EL display when an organic light emitting layer 63 is formed using the mask 2 shown in FIG. In the figure, for convenience of description, two same-color pixels 1a and 1b adjacent in the column direction are shown.

The components of each pixel are the same as in FIG.
The thin film transistors 13 and 42 and the storage capacitor 70 are formed in one pixel. These thin film transistors 13, 4
2 and the auxiliary capacitor 70 are collectively referred to as a switching element. The drain of the thin film transistor 13 is connected to the data line 52, and the source of the thin film transistor 13 is
And the thin film transistor 4
2 and the gate of the thin film transistor 13 is connected to the gate line 51. The source of the thin film transistor 42 is connected to the power supply line 53, and the drain is connected to the transparent anode 61.

However, in the present embodiment, the formation position of the anode 61 is different between two adjacent pixels 1a and 1b. That is, the anode 6 in the pixel 1a
The arrangement of 1 is the same as that of FIG. 10, but in the pixel 1b adjacent to the pixel 1a, the anode 61 is formed in the pixel 1b and close to the pixel 1a side. The switching elements of the pixel 1b, that is, the thin film transistor 13, the auxiliary capacitor 70, and the thin film transistor 42 are formed on the side of the pixel 1b remote from the pixel 1a and connected to the anode 61. Therefore, the anode 61 of the pixel 1a and the anode 61 of the pixel 1b are arranged to face each other, and the switching element of the pixel 1a and the switching element of the pixel 1b sandwich the anode 61 of the pixel 1a and the anode 61 of the pixel 1b. More specifically, the arrangement of the switching element and the anode 61 in the pixel 1a and the arrangement of the switching element and the anode 61 in the pixel 1b are in line symmetry with respect to a dashed line (boundary of the pixel) in the drawing. No switching element is interposed between the two anodes 61.

FIG. 3 shows a conventional two adjacent pixels 1.
The arrangement of a and 1b is shown. Conventional pixels 1a, 1b
Both have the same arrangement of the switching element and the anode 61. Focusing on the pixel 1b, the switching element is the pixel 1b.
And the anode 61 is on the side far from the pixel 1a. A switching element connected to the anode 61 of the pixel 1b is interposed between the anode 61 of the pixel 1a and the anode 61 of the pixel 1b. The difference between the present embodiment and the conventional anode 61 and switching element will be apparent.

As described above, in the present embodiment, two adjacent
In each of the pixels 1a and 1b, the anodes 61 are arranged close to each other, and respective switching elements for applying a voltage to the anodes 61 are arranged at both ends of the anode 61. Therefore, in the present embodiment, two adjacent anodes 61 can be arranged closer to each other than before, and the organic light emitting layer 63 can be formed in common on the two anodes 61 arranged close to each other. In addition, two anodes 61 arranged in close proximity
Since there is no anode between them, no light is emitted even when the organic light emitting layer 63 is formed, and the light remains emitted for each pixel.

FIG. 4 shows the relationship between the arrangement of the anodes of the pixels and the openings 2a in the present embodiment and the related art. FIG. 4A shows a conventional relationship, and FIG. 4B shows a relationship of the present embodiment. Conventionally, as shown in FIG. 3, since the anodes 61 of two adjacent pixels 1a and 1b are separated from each other and a switching element is interposed therebetween, an organic light emitting layer 63 is formed on each anode 61. The distance between the openings 2a (the length of the non-opening) is set to d, but in the present embodiment, the anode 61 is disposed between two adjacent pixels 1a and 1b.
Because they are opposed to each other (or close to each other),
The organic light emitting layer 63 can be simultaneously formed on the two anodes 61 with one opening 2a. Then, two adjacent pixels 1a and 1b are set as one set, and the distance between the adjacent sets is larger than before (see the arrow in the drawing). Length D
Is larger than the conventional length d between the openings 2a. Thus, the strength of the mask 2 of the present embodiment is higher than that of the conventional mask 2. In addition, the same opening 2a is provided for two anodes 61 of two adjacent pixels 1a and 1b.
Since the organic light-emitting layer 63 is formed in common, the number of openings at the ends of the mask 2 is halved, and the thickness of the organic light-emitting layer 63 can be made uniform by preventing a decrease in film thickness due to shadowing. Therefore, the current intensity in the region between the anode 61 and the cathode 66 is also uniform, so that the deterioration of the light emitting layer can be prevented and the light emitting area can be secured.

Although the embodiment of the present invention has been described above, the present invention is not limited to this, and various modifications can be made.

For example, in this embodiment, the case where the same color pixels are arranged linearly in the column direction has been described. However, the present invention can be similarly applied to the case where the same color pixels are arranged in a zigzag shape, for example, in a delta arrangement. . Hereinafter, the case of the zigzag arrangement will be described.

FIG. 5 shows the mask 2 of the present embodiment for forming the organic light emitting layer 63 in a zigzag arrangement. FIG. 6 shows a conventional mask 2 in a zigzag arrangement for comparison. As shown in FIG. 6, conventionally, the openings are also formed in a zigzag manner in the column direction corresponding to the zigzag pixel arrangement of the same color. The organic EL material that has passed through each opening is formed on the anodes 61 of the same color pixels arranged in a zigzag pattern. The length d between the openings of the mask 2 is small as in FIG. 12, and the strength of the mask 2 is also small.

On the other hand, in the mask 2 of the present embodiment shown in FIG. 5, since the organic light emitting layer 63 is shared between two pixels adjacent in the zigzag direction, the openings corresponding to the two adjacent pixels are also provided. It becomes common and becomes one elongated opening. Thereby, the distance D between the openings can be secured to be equal to or longer than the conventional length d on the basis of the same principle as in FIG.
Can be increased in strength. In FIG. 5, the opening of the mask 2 is formed not in zigzag but in one direction but obliquely. This is because the anodes of two adjacent pixels are arranged to face each other.
The details will be described later.

FIG. 7 is a plan view of two adjacent pixels 1a and 1b arranged in a zigzag pattern in the present embodiment. The pixel 1a has switching elements (thin film transistors 13, 42 and an auxiliary capacitor 70) and an anode 61, and the same applies to the pixel 1b. The connection relationship between the thin film transistor 13 and the data line 52 and the gate line 51 and the connection relationship between the thin film transistor 42 and the power supply line 53 and the anode 61 are the same as those in the above-described embodiment.
This is indicated by the ET symbol. The anode 61 of the pixel 1a and the pixel 1
The anode 61 of the pixel 1b is formed diagonally.
Focusing on, the anode 61 of the pixel 1b is arranged on the side of the pixel 1a in the pixel 1b and is arranged to face the anode 61 of the pixel 1a. The anodes 61 of the pixels 1a and 1b are point-symmetric with respect to the center of the center of the facing part of the anodes 61 at the boundary between the pixels 1a and 1b. Furthermore, both anodes 6
1, no switching element of the pixel 1a or the pixel 1b is interposed. Thus, two adjacent pixels 1
Since the anodes 61 of a and 1b are arranged so as to face each other and are close to each other, the organic light emitting layer 63 can be integrally formed using the mask 2 having an oblique opening. And
As shown in FIG. 7, the two adjacent anodes 61 are arranged opposite to each other and formed diagonally, and the organic light emitting layer 63 is formed with the mask 2 as shown in FIG. can do.

On the other hand, FIG. 8 shows a plan view of two adjacent pixels 1a and 1b arranged in a conventional zigzag pattern. Each of the pixels 1a and 1b has a switching element and an anode 61.
Numeral 1 is on the side of the pixel 1b remote from the pixel 1a.
The switching element of the pixel 1b is interposed between the anode 61 of the pixel 1a and the anode 61 of the pixel 1b. Anode 6
1 are spaced apart and a switching element is interposed therebetween, so that a mask 2 as shown in FIG. 6 is required to form the organic light emitting layer 63 on the anode 61.

By comparing FIG. 7 with FIG. 8, in this embodiment, since the anodes 61 are arranged close to each other and opposed to each other, the distance between the adjacent pairs is set to the conventional value by using two adjacent pixels as one set. It can be understood that the length D between the openings of the mask 2 in FIG. 5 is larger than the conventional length d. Thereby, the mask strength in FIG. 5 becomes larger than the mask strength in FIG. Therefore,
The thickness of the mask can be reduced to about 50 μm.
Also in this embodiment, two adjacent pixels 1
Since the organic light emitting layer 63 is shared by a and 1b, the number of opening ends of the mask 2 is reduced by half, shadowing is suppressed, and the film thickness of the organic light emitting layer is made uniform.

In this embodiment, the case where the organic light emitting layer 63 is formed by vapor deposition has been described. However, even when the organic light emitting layer 63 is formed by the ink jet method, the mask 2 shown in FIG. Which functions as a frame for dropping the organic light-emitting layer).

In the case of multi-panel formation in which a plurality of panels are simultaneously formed on one large substrate, the mask 2 shown in FIG. 1 or FIG. 5 can be used for each panel.

[0042]

As described above, according to the present invention,
The strength of the mask for forming the light emitting layer can be increased.

Further, according to the present invention, the thickness of the light emitting layer can be made uniform, thereby increasing the effective light emitting area.

[Brief description of the drawings]

FIG. 1 is a plan view of a mask according to an embodiment.

FIG. 2 is a plan view of a pixel according to the embodiment.

FIG. 3 is a plan view of a conventional pixel.

FIG. 4 is an explanatory diagram illustrating a relationship between a pixel arrangement and an opening according to the embodiment.

FIG. 5 is a plan view of a mask according to another embodiment.

FIG. 6 is a plan view of a conventional mask.

FIG. 7 is a plan view of a pixel according to another embodiment.

FIG. 8 is a plan view of a conventional pixel.

FIG. 9 is an explanatory diagram of a pixel arrangement.

FIG. 10 is a plan view of a conventional pixel.

11 is a sectional view taken along line AA of FIG. 10 and a sectional view taken along line BB of FIG.

FIG. 12 is a plan view of a conventional mask.

[Explanation of symbols]

1a, 1b pixel, 2 mask, 61 anode, 63 organic light emitting layer.

Continued on the front page F term (reference) 3K007 AB02 AB04 AB17 AB18 BA06 CB01 DA01 DB03 EB00 FA01 5C094 AA03 AA08 AA10 AA43 AA48 AA55 BA03 BA12 BA27 CA19 CA20 CA24 DA13 DB04 EA04 EA05 EA07 EB02 FA01 FB01 GB10

Claims (11)

[Claims] 1. A semiconductor device configured by arranging a plurality of pixels each having a light emitting layer provided between a first electrode and a second electrode, wherein the first electrode is provided for each of the pixels. Wherein the light emitting layer is shared by two adjacent pixels of the plurality of pixels, and the first electrodes of the two adjacent pixels are located on the side of another pixel adjacent to each other in the pixel. A semiconductor device characterized by being arranged. 2. A plurality of pixels each comprising: a first electrode and a second electrode; a switching element connected to the first electrode; and a light emitting layer provided between the first electrode and the second electrode. In the semiconductor device configured and arranged, the light emitting layer is shared by two adjacent pixels among a plurality of the pixels, and the first electrodes of the two adjacent pixels are arranged in a planar position. A semiconductor device characterized by being arranged opposite to each other without a switching element. 3. The semiconductor device according to claim 2, wherein the switching elements of the two adjacent pixels sandwich both ends of the first electrode so as to sandwich the opposed first electrode in a planar position. A semiconductor device, wherein the semiconductor device is arranged in a semiconductor device. 4. The semiconductor device according to claim 3, wherein the first electrodes and the switching elements of the two adjacent pixels are arranged symmetrically with respect to the axis of the opposed arrangement. Semiconductor device. 5. The semiconductor device according to claim 1, wherein the two adjacent pixels have the same color. 6. The semiconductor device according to claim 5, wherein the pixels of the same color are arranged adjacently in a column, and the light emitting layer is shared by two adjacent pixels in the column. Characteristic semiconductor device. 7. The semiconductor device according to claim 5, wherein the first electrodes are arranged point-symmetrically about a center axis of the opposed arrangement. 8. The semiconductor device according to claim 5, wherein the pixels of the same color are arranged in a zigzag pattern, and the light emitting layer is shared between two adjacent pixels in the zigzag pattern. Semiconductor device. 9. The semiconductor device according to claim 5, wherein said pixels of the same color are at least one of an R pixel, a G pixel, and a B pixel. 10. The semiconductor device according to claim 1, wherein the light emitting layer includes an organic electroluminescent material. 11. The light emitting layer forming mask for manufacturing the semiconductor device according to claim 1, wherein the mask has an opening common to the two adjacent pixels. A mask, wherein a material of the light emitting layer is passed through an opening to form the light emitting layer.