JPH0558169B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Application of the Invention The present invention provides a microcomputer,
The present invention relates to a semiconductor device having non-linear characteristics that is applied to a solid-state display device, an image sensor, or a liquid crystal printer that solidifies the display portion of a word processor or a television.

``Prior Art'' For solid-state display panels, a system in which each picture element is controlled independently is effective for large-area displays. A panel using such active elements is a display with a large area matrix configuration of A4 size or larger, with 640 elements in the horizontal direction (640 x 3 = 1920 elements in the case of full color) or 200 elements or 526 elements in the vertical direction. The device is known. However, in such a large-area display device, each active element (hereinafter also referred to as a pixel) has crosstalk (also referred to as a pixel) with its neighboring pixels, which are arranged in a matrix at a predetermined distance apart. (a phenomenon in which electrical conduction is weak) is likely to occur. Therefore, one side
Even if an ON function and an OFF function were created for each pixel, each pixel could not be turned on or off sufficiently, resulting in insufficient contrast.

"Problems to be Solved by the Invention" In such a large-area display device, in order to completely eliminate crosstalk between each pixel, semiconductors including amorphous semiconductors should not exist between adjacent pixels. At the same time, it is important to perform electrical isolation by covering with an insulating material. However, when each pixel and the semiconductor constituting the pixel were made to correspond on a 1:1 basis, four types of photomasks were required in the manufacturing process.

Therefore, when this photomask is used once, there are 7 steps (resist coating, baking, patterning, development, removing part of the resist,
This necessitates selective etching of the workpiece and removal of the resist, which poses a significant problem in lowering the manufacturing yield. For this reason, there has been a demand for a semiconductor device structure in which the number of mask alignments is only once for every two types, and in which crosstalk between adjacent pixels can be completely prevented.

"Means for Solving the Problem" In order to solve the problem, the present invention provides a display device in which a plurality of active element type pixels are provided in a matrix on a substrate, each pixel has a first electrode, a non-linear material , a non-linear element consisting of a stack of second electrodes, a third electrode connected to the first electrode of the element and serving as a pixel electrode, and a lead connected to the second electrode, The lead is one of the wirings constituting the matrix, and the lead is one of the wirings forming the matrix.
A display device characterized in that the non-linear element is provided across the electrodes and is provided in a portion where the third electrode and the lead overlap,
Furthermore, the display device is characterized in that the second electrode of each pixel and the nonlinear material under the electrode have approximately the same shape.

In the above, the structure in which the lead, which is one wiring of the matrix wiring, is provided across a plurality of pixel electrodes means that this lead is provided so as to cross the plurality of pixel electrodes.

This configuration is illustrated in FIG. 4A of the drawings depicting an embodiment of the invention.

Specifically, the display device using the present invention has a common pattern for the electrode of the liquid crystal (third electrode) and one electrode (first electrode) of the nonlinear element, and It has a structure in which the sides of the semiconductor are insulated to provide isolation. Further, a lead extending from the second electrode on the semiconductor traverses the insulating film (actually, the side surface) and is connected to another second electrode of an adjacent pixel by a conductor. As a result, since mask alignment uses a self-alignment process, only two masks are required, and no semiconductor remains between adjacent pixels.
As a result, we were able to completely prevent crosstote. In addition, the semiconductor's periphery (electrodes on the top and bottom) is covered with an insulating material and is packaged.
This passivation film also prevents crosstalk between pixels.

Furthermore, the nonlinear element used in this invention uses a non-single crystal semiconductor, and its material composition is Si(N)−SixC _1- x
(0<X≦1)(I)-Si(N) structure, Si(NIPIN) structure or Si(N)-SixC _1- x(0<X<1)(I)-SixC _1- x
(0<X≦1)(I)−SixC _1- x(0<X<1)(I)−Si
(N) structure (where N is N-type, I is intrinsic or substantially intrinsic, P is P-type, and (I) is a barrier layer) or its tandem laminated structure and modified structure. I am the lord.

The nonlinear element used in the present invention has ohmic contact with a pair of electrodes (first and second electrodes), and is composed of an element having a composite diode that has reverse rectification characteristics. is an N-type semiconductor-type (hereinafter referred to as intrinsic or substantially intrinsic) semiconductor-N-type semiconductor layered.
NIN structure, that is, NI junction and IN junction are electrically connected in opposite directions and integrated as a semiconductor.
Semiconductors with NIN junctions, their variants NN ^- N, NP ^- N, NIPIN, NIP ^- IN or
It is a composite diode with an NIP ⁺ IN structure (hereinafter, for simplicity, these diodes will be collectively referred to as NIN type diodes).

The threshold voltage of such a composite diode makes the diode characteristics opposite to each other, and the build-in voltage (threshold) determines the conductivity type at or near the NI interface of the NI junction (NIP junction). Impurities such as trace amounts of phosphorus,
It can be determined by the height difference between the energy edges at the NI interface and the IP interface. Therefore, by controlling the manufacturing process, it is possible to control the value of the threshold voltage of a desired element, and the difficulty with which current flows below the threshold and the ease with which current flows above the threshold.

Furthermore, the present invention can be completed by simply aligning one mask in which the X wiring constituting the composite diode and the matrix and the nonlinear element thereunder have approximately the same shape. One electrode (third electrode) of the display and one electrode (first electrode) of the connected composite diode are connected to a common rectangular electrode, and an X or Y wiring (X wiring in the drawing) on the semiconductor above the common rectangular electrode. Therefore, the process can be carried out using only two masks, each consisting of a second mask, which is necessary for forming the X wiring (representatively shown below as an X wiring). A typical example of the structure of the present invention is shown in FIG. 4, and its manufacturing process is shown in FIG.

Furthermore, for solid-state display elements such as liquid crystals, AC bias is applied to the other electrode (fourth electrode) of the liquid crystal, leads are wired in the Y direction, and the electrical level is controlled to achieve full color and gradation. It also has the feature of being controllable.

``Function'' In this way, even when creating a matrix with a large area of A4 size or larger, the leads in the X direction can be arranged closely on the insulator in the stripe section between each pixel, and each pixel can be Passivation made it possible to eliminate electrical leakage from adjacent elements. In addition, by making the second electrode and the lead connected to it the same width, alignment accuracy in the X direction can be reduced to ±200 μm or less (theoretically within ±3 mm). The process is now possible with precision alignment.

In addition, as shown in Figures 1 and 4, the other Y wiring and electrodes of the liquid crystal are divided into three parts, and red (referred to as R) and green (referred to as G) are connected to each electrode or active element. , blue (referred to as B)
By passing the voltage through the filter, voltage can be applied independently to that level on the Y axis. Therefore, it has the feature that it is possible to perform gradations for R, G, and B.

The present invention will be described below with reference to Examples.

Example 1 FIG. 1 shows a circuit diagram using a solid state display device of the present invention.

In the drawing, the picture element is located closer to one electrode 23 of the liquid crystal 3 than the electrode 21 (first electrode) of the composite diode 2.
(third electrode). The compound diode is connected to the address line 4 of the X wiring that provides the clock signal.
5 by a second electrode 22. On the other hand,
The fourth electrode 24 of the liquid crystal 3 is connected to the data line 6 of the Y wiring,
It is connected to 7. Y wiring has one third electrode 2
The fourth electrode 24 (the first
6-1, 6-2, 6-3, i.e. 6 or 24) in FIG.
0'))) are connected in correspondence with each other. And this fourth electrode 14 is R (red), G (green), B
It has a (blue) filter and is full color.

This X wiring is provided on the same insulating substrate, typically a glass substrate (20 in FIGS. 4B, C, and D). As a result, crosstalk 33 is likely to occur, and the resistance of this part should be set to 10 ⁹ Ω or more, preferably
It is an object of the present invention to set the resistance to 10 ¹⁰ Ω or more.

These picture elements are arranged in a matrix, which is shown in the drawing as 2×2×3 (R, G, B). However, the present invention does not use such a small matrix, but a scaled-up display device, for example (640 pixels x 3 pixels).
It is effective for large matrix panels such as (R, G, B) x 200 or 512).

Examples of the manufacturing process and characteristics of a nonlinear element that is a part of a pixel using such a composite diode are shown in FIGS. 2 and 3.

The manufacturing process shown in Fig. 2 is 3 in Fig. 4A.
This corresponds to the case where the 0 area is particularly enlarged and manufactured.

FIGS. 2A, B, C, and D-1 correspond to the longitudinal cross-sectional views of FIG. 4 A-A'. FIGS. 2D-2 and 2E correspond to longitudinal cross-sectional views taken along line C-C' in FIG. 4, and show the device structure.

In FIG. 2A, non-alkali glass 20 was used as the light-transmitting insulating substrate. A conductive film is applied to this upper surface by sputtering or electron beam evaporation.
An ITO or tin oxide film was formed to a thickness of 0.1 to 0.5 μm.

After this, NIN (N(I)I(I)N, NIPIN, N(I)IPI(I)N) was formed on these entire surfaces using a plasma gas phase reaction method.
A composite diode made of a non-single-crystal semiconductor with a structure including That is, a non-single-crystal semiconductor having an amorphous structure is formed on a surface of a substrate maintained at 200 to 300° C. by subjecting an N-type semiconductor to silane and subjecting it to high-frequency glow discharge at 13.56 MHz. Its electrical conductivity is 10 ^-7 to 10 ^-4 (Ωcm)
^-1 and a thickness of 50 to 500 Å. Further next,
Sufficient vacuum was drawn to 10 ^-6 to ^{10 -7} torr. Furthermore, using silane (SimH _2n+2 , e.g. SiH ₄ with m=1), an I-type non-single crystal semiconductor is laminated on the N-type semiconductor to a thickness of 500 Å to 1 μ, for example, 0.2 μ. It was formed by Furthermore, sufficient vacuum was drawn to 10 ^-6 to 10 ^-7 torr. Again, B ₂ H ₆ /SiH ₄ =0.1%, and a P-type semiconductor was formed with a thickness of 100 to 500 Å, for example, 200 Å. Similarly, an I-type semiconductor layer (500 to 2000 Å), and an N-type semiconductor layer on top of it as an amorphous structure.
NIPIN junction or N
(I) IPI (I) N junction ((I) is a barrier layer (thickness 5-50 Å)
However, it is omitted below for brevity).

After this, apply chromium (500 to 1500 Å) on this top surface.
0.1 by electron beam evaporation method or sputtering method.
The layers were laminated to a thickness of ~0.2 μm.

Further, as shown in FIG. 2B, anisotropic plasma etching was performed using a first photomask so that the peripheral portion 26 was vertically etched. Next, plasma oxidation is performed on the semiconductor at, for example, 200°C on these entire surfaces.
Silicon oxide was prepared by solid phase-vapor phase oxidation.
Next, silicon nitride or silicon oxide 27 is applied to these entire surfaces.
Coating (particularly the coating on the side surface 26) was performed by plasma CVD method to a thickness of 0.1 to 0.2 μm.

Next, as shown in FIG. The top and the top of the substrate 20 were removed. Thus, Figure 2C was obtained. That is, next this second
Aluminum was formed on the entire upper surface of Figure C to a thickness of 0.5 to 1 μm to obtain Figures D-1 and D-2. After this, as shown in FIG. 2E, the first side surface 2
Patterning was performed using a second mask in the direction perpendicular to 6. In this way, the lead that is more ductile than the second electrode of one pixel extends over the insulator provided on the side surface of the first electrode in the semiconductor constituting the pixel, and is connected to the second electrode of the adjacent pixel. I was able to do it.

Furthermore, an insulator 29 similar to 28 may be formed on this side surface after this.

If the number of masks is to be increased, it is also possible to use the method shown in FIG. 2C in which one mask is used and the side surfaces and their vicinity are left by a normal plasma etching method. However, in such a case, the total number of masks used will be less than three.

That is, in FIG. 2, a first electrode 21 made of a transparent conductive film on a glass substrate 20, a composite diode 2 made of a NIPIN or NIN semiconductor stack,
It consists of a second electrode 15 made of chromium and an electrode lead 22 made of aluminum 16. this
The symbol for the NIPIN or NIN structure is marked as 2 in FIG.

As a result, a nonlinear characteristic 3 as shown in Fig. 3 is obtained.
Embodiment 2 In which the configuration of the present invention is shown in FIG. 4, a plan view A and a longitudinal cross-section of the area 1 surrounded by the broken line in FIG. Figures B, C and D are shown.

Further, FIGS. 4B, C, and D show longitudinal cross-sectional views taken along A-A', B-B', and C-C' in A, respectively.
In addition, FIG. 4C shows the liquid crystal 3 and the upper electrodes 6, 7.
and the substrate 20' are also shown, but other A, B,
D shows only the side having the nonlinear element for simplicity.

The manufacturing method of this element is the same as in Example 1.
That is, the rectangular first electrode 2 is formed using the first mask.
A semiconductor having the same shape and a conductor constituting a part of the second electrode are formed on the first and third electrodes 23 and thereon. The shape of the transparent conductive film constituting the first electrode and the second electrode was 420×420 mμ. Further, these constitute a passivation film for insulating the side surfaces of the semiconductor and the lower first and second electrodes. Furthermore, lead material for the upper electrode is formed over the entire surface. Next, the electrodes 1 constituting the leads 4 and 5 are exposed using a second photomask.
6 and the second electrode 15 with the same width (here, 20μ).
The aluminum was plasma etched using CCl ₄ in step m). Semiconductor 2 was removed by etching.

At this time, the first pixel electrode 2 on the lead 4
2, the electrode 22' of the second pixel next to this, and the lead 25 between them (FIG. 4B) are made to have the same width, so that they can be constructed at the same time even against horizontal pattern deviation. Then, the semiconductor is removed from the open groove between the two semiconductors 2 and 2', and the leads are removed from the insulator 2 on the side of the semiconductor.
8, 28' and on the substrate 20.
That is, since the two semiconductors 2, 2' are isolated by the insulators 28, 28', the equivalent resistance, which is less likely to cause crosstalk, can be reduced to a substantially infinite value of 10 ⁹ Ω or more.

Furthermore, since the second electrode is provided above the rectangular first and third electrodes, its position is ±200 μ above and below the original position at the center.
Even if there is a shift of m (maximum), the electrode area of the nonlinear element remains unchanged, and patterning is possible without significantly affecting the electrical characteristics (current value). In other words, in a 640 x 512 element, for example, the top right edge and bottom left edge of a glass substrate (30 cm x 20 cm) may be misaligned, resulting in a mask misalignment that is 10 times that of the conventional mask. Mask alignment is now possible even with poor accuracy.

Thus, the second
By using the mask, it was possible to form the composite diode 2 in approximately the same shape on the third electrode 15.

Furthermore, as is clear from FIG. 4B, crosstalk resistance exists between the first electrode 21 of the element that controls one pixel and the first electrode 21' of the element that controls the adjacent pixel. 33 has a gap of 15 μm without any semiconductor remaining, and each semiconductor is covered with an insulating film 26, so it has a high resistance of 10 ¹⁰ Ω or more (when the width of the lead 25 is 20 μm).
It had

Furthermore, the other fourth electrode 24 of the opposing liquid crystal,
24' and leads 6 and 7 were formed as wiring in the Y direction using another first mask.

After this, for each wiring in the Y direction,
By a known electrodeposition method, red filters were applied to the electrodes 6-1 and 7-1, green filters were applied to electrodes 6-2 and 7-2, and blue filters were applied to electrodes 6-3 and 7-3. formed. Then polyimide e.g.
In addition to coating PIQ as a protective film, this
Orientation treatment was applied to PIQ.

For this full coloring, a dyeing method may be used instead of the electrodeposition method. In this method, R, G, and B filters are first formed on a glass substrate, then a passivation film is formed, and 6-1, 6-2,
Electrodes were formed by dividing it into three parts: 6-3, 7-1, and so on.

In this way, three electrodes could be provided corresponding to one lower electrode.

From the above, it is only necessary to use three types of masks to form one active picture element on this surface, and especially in that case, two overlapping masks (one
It has the advantage of requiring only 10 times).

Furthermore, another opposing insulating substrate 20' is
After evacuating the space with a width of 10 μm, a known liquid crystal 10 was sealed.

For the display panel, a reflective plate is then provided for the reflective type, a light source is provided on the back side for the transmissive type, and a first
The peripheral circuits 8 and 9 shown in the figure were arranged on a printed circuit board, and the leads of the printed circuit board and the leads of the display element were connected in correspondence with each other.

In this way, it has become possible to pattern an active element type panel using only three masks.

"Effects" As described above, the present invention eliminates crosstalk between a pixel made of a nonlinear element and a liquid crystal and an adjacent pixel. In addition, the electrode area (current value when applying a predetermined voltage) of a nonlinear element changes even if it is shifted up to ±200 μm vertically from the center of the rectangular electrode, or by several mm left and right. has certain nonlinear characteristics,
It was possible to prevent variations in the electrical characteristics of the active drive throughout the matrix.

It is an alternating current drive system, and in particular, the threshold value of the diode can be controlled by the process conditions during stacking of semiconductor layers using a gas phase reaction method, making it easy to control gradation.

In the present invention, a nonlinear element NIN junction or
NIPIN joint was used.

Furthermore, NIPIN, which sets up a tandem,
The threshold value may be increased as a NIPINIPIN junction.

However, on the other hand, diode rings with multiple PIN junctions in parallel, or BACK with multiple PIN junctions in series,
The present invention is also effective for other nonlinear semiconductor devices having the origin symmetric characteristic shown in FIG. 3 using the -TO-BACK method and other Zener characteristics or avalanche characteristics.

In the present invention, when the non-linear element is non-photosensitive, it is possible to provide the first electrode with only a light-transmitting conductive film and provide a semiconductor closely thereto. In addition, when the device is photosensitive and uses the dark state of the device, it is necessary to provide a light-shielding conductor, such as chromium, in the same shape as the semiconductor between the rectangular transparent conductive film and the semiconductor. Needless to say.
Of course, even if the nonlinear element has photosensitivity and its photosensitivity is utilized, the present invention may be applied according to the application.

[Brief explanation of the drawing]

FIG. 1 shows a circuit diagram of a liquid crystal display panel using the configuration of the present invention. FIG. 2 is a vertical cross-sectional view showing the manufacturing process of the composite diode used in this example. FIG. 3 shows the operating characteristics of the composite diode nonlinear element used in this example. FIG. 4 shows a plan view and a longitudinal sectional view of the display panel according to this embodiment.

Claims (1)

[Scope of Claims] 1. In a display device in which a plurality of active element type pixels are provided in a matrix on a substrate, each pixel is a nonlinear element consisting of a stack of a first electrode, a nonlinear material, and a second electrode. a third electrode connected to the first electrode of the element and serving as a pixel electrode; and a lead connected to the second electrode, the lead being one of the wirings constituting the matrix. , and the lead is connected to a plurality of the third leads.
A display device characterized in that the non-linear element is provided across the electrodes and is provided in a portion where the third electrode and the lead overlap. 2. A display device according to claim 1, wherein the second electrode of each pixel and the nonlinear material under the electrode have approximately the same shape.