JPH032309B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses an insulated gate field effect semiconductor device (hereinafter referred to as IGF) to control and display each group of picture elements arranged in a matrix. Display devices, especially electroluminescent or voltage-driven light emitters, e.g. electroluminescent (EL)
The present invention relates to a display device.

This invention uses electroluminescence that emits light as an active element, and applies a voltage or current to the first electrode of each picture element and this picture element to control the presence or absence of an electrical signal. An EL is provided on one substrate, an EL is provided on the second electrode of the other substrate, and the EL is provided on the second electrode of the other substrate.
A third electrode is provided on the back surface of the electrode, and the third electrode and the first electrode are connected by filling with a conductive material.

In this invention, when filling this conductive material,
The feature is that each active element is filled with an integrated filling material, rather than being separated using a mask process (isolation). In other words, the electrical conductivity (connection resistance) between the first electrode and the third electrode in a certain element is sufficiently larger than the electrical conductivity (isolation resistance) between the third electrode of the adjacent picture element ( (sufficiently small) (preferably having a value of ¹⁰² or more), it is possible to effectively isolate each picture element without intentionally morphologically insulating (isolation) between each picture element and without requiring any extra process. The feature is that it is isolated and integrated.

Conventionally, in such a semiconductor display device, a group of picture elements arranged in a matrix in a display circuit connects one IGF2 and a display element (here, an LCD) in series, and connects the gate electrode of this IGF in the X direction.
Also, the source and drain were arranged in the Y direction.

However, although it has been possible to form non-light-emitting elements such as active elements for LCDs or ECDs (electrochromics) into a matrix, it is currently impossible to form active elements that emit light themselves into a matrix.

Further, although there are two substrates in a display device, IGF is provided on one substrate, and CTF is simply provided on the entire surface of the other substrate, and the LCD is filled between them.

In the present invention, green light emitting bodies (of course, other color or full color light emitters may also be used), particularly voltage-driven light emitters (hereinafter simply referred to as EL), are formed into a matrix and used as a semiconductor display device.

FIG. 1 shows a circuit diagram of a semiconductor display device using the EL of the present invention.

As is clear from the drawing, the element is one
It is provided with IGF2 and one EL1.

However, one electrode of IGF2 (first electrode 22)
A third electrode 33 is provided between the EL1 and the EL1, and a resistive conductive material 6 is provided between the third electrode and the first electrode 22 connected to the IGF. It is being filled.

On the other hand, the electrode (second electrode) 3 on the side of the EL that is not connected to the IGF is held at a common ground level, and the voltage level is common to all elements.

In the present invention, the IGF and the first electrode in such a circuit configuration are provided on the first substrate. Generally, 6 to 8 masks are used to manufacture this IGF. On the other hand, the EL is fabricated on the second substrate and the CTF (transparent conductive film) electrode thereon by vacuum evaporation, sputtering, or the like. Furthermore, a third electrode as a back electrode of the EL was selectively fabricated on top of that. That is,
Since the substrate on which the EL material is made is different from the substrate on which the IGF is formed, the reliability of the IGF itself may be reduced,
Does not cause yield drop again.

Furthermore, a resistive conductive material is filled between the third electrode and the first electrode on the back side of this EL, and the two electrodes of each element are integrated without being connected one by one by soldering etc. I fill it up as something.

At this time, since the EL is a voltage-driven type, it is important that the resistance of this conductive material is smaller than the resistance of the EL itself. That is, the resistance between the first and third electrodes (hereinafter referred to as connection resistance) has a smaller value than the resistance between the electrodes of the adjacent picture elements (hereinafter referred to as isolation resistance). It is said that

Furthermore, the present invention provides a voltage-driven light emitter (hereinafter simply referred to as
Regarding EL), the first electrode is RGB (red, green,
By dividing the color into three primary colors (blue) and connecting them in the X or Y direction, it is possible to construct a so-called full-color display.

The first and third electrodes of a picture element connected to one IGF are one, but the other electrode, which is the other electrode that opposes this electrode, is
Because RGB is provided, there are three. As a result, in terms of manufacturing, each of the two independent substrates is first manufactured, quality inspected, and then good quality products from each product are combined to produce a final finished product with a high yield.
As a result, it has the great feature that the yield of semiconductor display devices can be greatly improved.

FIG. 2 is a circuit diagram of the present invention that provides full color display. The drawing is 3x3 for simplicity.
(When RGB is divided, it is arranged in a 3x3x3 matrix). In other words, although there are 27 independent picture elements, the matrix has only 9 IGFs, which is a great feature.

In FIG. 2, the spacing between adjacent counter electrodes 3, 3', 3'', which are second electrodes, ie, the spacing between 3, 3', 3'' is 30 to 100 microns. In contrast, the region 6 filled with the material is extremely thin, with a thickness of 1 to 5 μm.
Therefore, the voltage applied by the IGF is
Through this process, sufficient voltage could be applied to the EL main body 1. Even though this conductive material 6 is continuous with its neighbors, the isolation resistance with the electrode of the adjacent picture element is more than ¹⁰ times larger than the connection resistance, so it is difficult to operate a certain picture element. It has been found that when the user is using the device, so-called ghosting, which causes neighboring picture elements to operate simultaneously, does not occur and does not cause discomfort to the user.

In Figure 2, the active element is the first element directly connected to the source or drain of one IGF2.
electrode 22 and a voltage-driven display element (here,
EL) a third electrode 33 in close contact with 1, 1', 1'';
33', 33'', with a conductive material 6 between them.
is filled. These ELs may be removed by etching using the third electrode as a mask, or may be left as is if the resistance is greater than the isolation resistance. Furthermore, the other one is a second one corresponding to the size of the R, G, and B color filters.
3, 33', 3 constitutes the second electrode in the figure.
11, 12, 1 to the color control decoder 9 as 3''.
3...11'', 12'', 13'', the other drain or source of the IGF is connected to the leads 5, 5', 5'' in the Y direction. Also
The gate electrodes of the IGF are connected in the X direction 4, 4', 4''.

In the drawing, one first substrate is provided with decoders 7, 8, IGF1, and one first electrode for a display element, and the other transparent second substrate is provided with
The second electrode of the CTF was divided into three parts and connected in the X direction.

In FIG. 2, electrodes and leads for RGB are connected in the X direction, and these are connected to a color classification control circuit (decoder) 9.

Furthermore, EL is placed on this second electrode in the same way as in Figure 1.
was formed by a vapor deposition method or a sputtering method to further constitute a third electrode. The third electrode is a reflective electrode, and a reflection promoting film tuned to half the wavelength of the light emitting source is provided between the third electrode and the EL material to sufficiently reflect the light generated on the third electrode side. Light was diffused from the electrode side of No. 1 to the outside.

3 and 4 show a plan view and a longitudinal sectional view of the semiconductor display device of the present invention.

This drawing corresponds to the circuit configuration of FIG. 1.

In the drawing, on a substrate 25 having an insulating surface
Two IGFs 2 and 2' are arranged in parallel in a pair. This is important for increasing the driving ability of the IGF, and even if one IGF develops a short or open defect (especially a short defect), that IGF can be removed by laser trimming, and only the other IGF can be used to drive the display element. This provides redundancy by driving the

Regarding this vertical channel type IGF, FIG. 3B shows a longitudinal cross-sectional view taken along line A-A' in FIG. 3A.

In the drawing, the lower electrode 14 of IGF2 is connected to the first electrodes 22, 22'. This electrode 14
A source or drain 15 (thickness: 500 to 3000 Å) as a stack having the same shape on top of the stack 16
(thickness 0.5-5μ) (actually used silicon nitride film), drain or source 17 (thickness 500-3000Å), Y
Electrode 18 (thickness 1000 to 5000
), interlayer insulating film 19 (0.5~3μ) (actually PIQ
) is provided. Furthermore, these are covered with hydrogen or a halogen element (preferably fluorine).
A non-single-crystalline semiconductor (including an amorphous structure) 21 doped with is covering these stacked bodies with a thickness of 0.1 to 0.4 μm.

MS (methylsilane) with some carbon added to increase the breakdown voltage of this non-single crystal semiconductor
For example, it was fabricated using a gas mixture of H ₂ Si (CH ₃ ) ₂ and SiH ₄ at a temperature of 200 to 300° C. by a plasma vapor phase method. In this embodiment, it is necessary to apply a voltage of nearly 100 V to the electrodes of the EL, so an attempt was made to improve the withstand voltage in the channel forming region 21.

This semiconductor 21 and the layers 15 and 17 constituting the P or N type source and drain are in ohmic contact. A silicon oxide or silicon nitride film (thickness: 500 to 3000 Å) is formed on this semiconductor layer as a gate insulator, and a gate electrode made of semiconductor, chromium, titanium, molybdenum, tungsten, or a compound thereof (thickness: 300 to 3000 Å) 20 has been established. This gate electrode is connected to leads 4, 4', and 4'' that constitute the bus line in the X direction.
It has a thickness of 0.5-3μ. Its sheet resistance is 0.5
Keep it below Ω/□.

After this, excluding the first electrodes 22, 22',
The other leads 4'', IGF2, 2', etc. are covered with an insulator 39, which is made of organic resin to prevent electrical shorts from occurring between the IGF2, 2' and the electrodes 33, etc., especially in subsequent steps. Covered with insulator.

Further, the second substrate 26 has a second electrode.
CTF3 was formed from fluorine-doped SnO ₂ or ITO.

In this example, the EL material is a laminate of zinc selenide (ZnSe) and zinc sulfide (ZnS) formed by a sputtering method or an electron beam method. In this example, TbF was mixed into ZnS to emit green light. In this way, the EL light emitter 41 was constructed.

Furthermore, a mask is used on this upper surface (the lower side in Figure 3B), and a thickness of 1400 mm is used to increase the reflection of the green color.
The reflection-enhancing film 42 tuned to the half wavelength of Å and green is made of dielectric material such as Y ₂ O ₃ , BaTiO ₃ or ITO.
Alternatively, SiO ₂ was used and provided on the EL. In addition, reflective metals 33, 33' (aluminum in this case) having a thickness of 0.2 μm to 0.5 μm were formed on the upper surface thereof.

Thus, on the first substrate 25, the IGF and the first
22, and a CTF as a second electrode on the second transparent substrate 26 (lower in FIG. 3B).
3. An EL light emitter 41 and third electrodes 33 and 33' were provided.

Next, after testing each of these in advance and confirming that they were good products, a conductive material 40 was provided in liquid form on the first substrate 25 on which the IGFs 2 and 2' were formed in a matrix. For example, an epoxy conductive paste, such as a copper paste or a silver paste, or a conductive rubber was used. These were applied onto one substrate and aligned with each other.

As a result, the first
It was possible to connect the electrodes 22, 22' and the third electrode 33 without electrical bonding.

This electrically conductive material 40 has a thickness of 0.3-5μ, for example 1μ, and its area has the area of the first electrode, so that the resulting resistance was 10-100Ω. However, on the other hand, the third electrodes 33, 33' are separated from each other by more than 50μ, and in addition, the area (thickness width of 33, 33') is small, so the isolation resistance 36 is 10KΩ to 200KΩ. had. In other words, one IGF could emit the corresponding EL without having to form an isolation structure in terms of shape.

Even though this EL is formed as one 41 as a whole, each dot part of one electrode 33, 33' formed into a matrix can be driven by turning on and off the voltage applied to the corresponding IGF. did it.

FIG. 4 shows a longitudinal sectional view taken along line BB' in FIG. 3A. From the drawing, the IGF2 is provided in a laminated manner on the substrate 25, and the electrodes 33 of the EL display element 41,
33' is electrically connected to the first electrodes 22, 22'. In order to improve the contrast by making the EL light emitting body in the display element 41 reflective, one of the substrates 26 is transparent and made of glass or Sumilat 1300 (abbreviated as PES) manufactured by Sumitomo Bakelite Co., Ltd.
may also be used. As the other substrate 25, it is effective to use a stainless steel substrate with an insulating film formed of plastic or the like.

With the above configuration, a solid state display device of 20 inches or more could be obtained.

Here, on a trial basis, 100 x 100 elements are 5 cm x 5 cm.
, the first electrode or current line 5,
5′, 5″ and the second electrode 3, apply 80V,
By selectively applying and controlling a gate voltage of 0 or +10V to 4, 4', and 4'', we were able to create an active element that selectively emits light only at a predetermined address.In this way, we were able to create a matrix using EL light emitters. We were able to obtain a semiconductor display device.

The present invention effectively uses each substrate,
Since the EL section on one side and the control section on the other side were provided in advance and the good products were integrated, the yield was significantly improved. With the conventional method, if a 100 x 100 panel with 1% or less defects is considered a good product, a yield of only 3% can be expected. However, in the structure of the present invention, it was possible to obtain even a lot of more than 10%.

Therefore, it has been found that when the number of elements increases to 525×640, the effects of the present invention can be expected to further increase.

In the configuration shown in FIG. 3 in this specification, the second
It is possible to provide the circuit shown in the figure with some modifications.

That is, the CTF of the second electrode 3 may be divided into one or more parts according to the size of the third electrode of each picture element.

Furthermore, in the present invention, it is effective to provide the antireflection film 27 on the side that is viewed by a person, for example, on the upper surface of the substrate 26.

Additionally, in the present invention, the IGFs were of the vertical channel type and were used in pairs. But this 1
Needless to say, it may be a single IGF or a horizontal channel type IGF.

An embodiment of this invention is a green light emitter (emission voltage 70~
90V) was used. However, to achieve more complete crystallization in ZnSe and TbF ₃ , driving at 5 to 10 V is possible. Furthermore, the circuit shown in FIG. 2 can be used as a monochromatic high-resolution display device if an RGB filter is not provided on one side of the substrate.

In Figure 3, the side that people view is the upper side. However, it is also possible to make this side the lower side (25 side). In such a case, the substrate 21, the filler 40, and the first and third electrodes 22 and 33 may be made translucent, and the second electrode 3 may be provided as a reflective electrode on which a reflection promoting film is formed.

In addition, in such a case, since the EL itself can be driven at low pressure and has high efficiency, the filling material 4
LCD/EL with 0 as LCD and 41 as EL
Needless to say, it is also possible to construct an integrated structure.

[Brief explanation of the drawing]

FIG. 1 shows a circuit diagram of a conventional display device. Second
The figure shows a circuit diagram of a display device of the present invention. Figure 3,
FIG. 4 shows an electrical diagram and a longitudinal sectional view of a semiconductor display device of the present invention provided corresponding to the circuit of FIG.

Claims (1)

[Claims] 1. A first electrode and a semiconductor device for controlling the presence or absence of an electric signal to the electrode are provided in a matrix on a first substrate having an insulating surface, and are spaced apart from the substrate. A second electrode, a light emitter, and a third electrode are provided in a matrix on a substrate having a second electrode provided thereon, and the first electrode and the third electrode are arranged in a ratio of 1:1. 1. A semiconductor device, wherein the first electrode and the third electrode are arranged as a pair and face each other, and the first electrode and the third electrode are electrically connected by a conductive material. 2. A semiconductor display device according to claim 1, characterized in that the resistance between the third electrode and the first electrode is sufficiently smaller than the resistance between the adjacent picture element. 3 In claim 1, one or more second electrodes arranged in pairs on the first electrode
A semiconductor display device characterized in that the electrodes are connected in the X direction or the Y direction.