JPH0462569B2 - - 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 method for manufacturing 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 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) and 200 elements or 526 elements in the vertical direction. equipment is required. However, in such a large-area display device, picture elements (hereinafter also referred to as pixels) each having an active element are arranged in a matrix shape with a predetermined distance between them.

However, the upper surface of one electrode of this pixel is required to be flat for the dubbing process for alignment, especially in liquid crystal display elements. Furthermore, if the electrode has a convex shape, it will peel off from the substrate surface during the dubbing process, causing a decrease in yield, and there is no display panel that completely solves these problems. is the current situation.

"Problems to be Solved by the Invention" In such a large-area display device, in addition to completely eliminating crosstalk between each pixel, it is necessary to prevent peeling of active elements and lead wiring from the substrate. It is extremely important.

In addition, especially in such display devices, in order to achieve a field of view ratio (aperture ratio) of 80% or more, the width of the lead wiring must be approximately 20 μm, and peeling may occur due to the difference in thermal expansion coefficient between the lead wiring and the glass substrate. was more likely to occur. In addition, in an active display device, each pixel and the semiconductor connected to that pixel are 1:
1, four types of photomasks were required in the manufacturing process.

If this photomask is made once, it requires seven steps (resist coating, baking, patterning, development, partial removal of resist, selective etching of the workpiece, and removal of resist).
This has become a huge hindrance to increasing manufacturing yields. For this reason, there has been a need for a method for manufacturing a semiconductor device in which the number of mask alignments of two types is only one, and crosstalk between adjacent pixels can be completely prevented.

"Means for Solving the Problem" In order to solve this problem, the present invention includes a nonlinear element having a semiconductor under the second electrode and a first electrode thereunder. The periphery of this nonlinear element is filled with an insulator. By making the upper surface of this insulator approximately coincide with the upper surface of the second electrode (each surface is smoothly continuous), the surface of the pixel (the surface of the third electrode) was made flat.

Further, a liquid crystal electrode (third electrode) is provided in close contact with the second electrode on the non-linear element so as to cover the semiconductor and the insulator on the side peripheral surface thereof. In this way, dubbing for liquid crystal alignment can be easily performed on the third electrode without inducing peeling of the nonlinear element and the leads on the polyimide resin coated on the third electrode. It became possible.

Further, the first pixel and the adjacent second pixel are connected in close contact with the glass substrate, with the first electrodes of each pixel extending over the substrate.
As a result, since the mask alignment process uses a self-alignment process, it has become possible to align the masks only once (with two masks).

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.

The nonlinear element used in the present invention has ohmic contact with a pair of electrodes (first and second electrodes), and is composed of a composite diode that has reverse rectification characteristics. An example is an N-type semiconductor (Si) doped with hydrogen or a halogen element - an I-type (hereinafter referred to as intrinsic or substantially intrinsic) semiconductor (SixC ₁ - xC<0<X≦1)) -
NIN structure with stacked N-type semiconductors (Si),
In other words, semiconductors include NIN junctions in which NI junctions and IN junctions are electrically connected in opposite directions and are integrated as a semiconductor, as well as its variants NN ^- N,
It is a composite diode with an NP ^- N, NIPIN, NIP ^- IN, or NIP ⁺ IN structure (hereinafter, for simplicity, these are collectively referred to as NIN type diodes).

Further, in the present invention, the line width of the X wiring or Y wiring (hereinafter referred to as the X wiring as only the X wiring is shown in the drawings) constituting the composite diode and the matrix and the width of the nonlinear element thereon are approximately equal to each other. They have the same shape and can be completed with only one mask alignment. A typical example of the structure of the present invention is shown in the fourth example.
The manufacturing process is shown in FIG.

Furthermore, for a solid-state display device such as a liquid crystal display device, the alternating current bias is connected to the other electrode (fourth electrode) of the liquid crystal, the lead is wired in the Y direction, and the electrical level is controlled to achieve full color and gradation. It also has the feature of being able to be controlled.

"Operation" Thus, the organic resin film around the side of the laminate can be selectively removed by coating the laminate with a photosensitive resin and irradiating it with light from the transparent glass substrate side. By removing unnecessary resin from the laminate while leaving the side periphery, the surface between the electrode surface on the laminate and the resin can be made approximately flat, and in addition, a crevice gap can be created between the laminate and the resin. I was able to flatten it without tightening it. In particular, this could be achieved by using the electrodes on the laminate as a mask for ultraviolet light without using any extra mask. This means that even for large-area substrates, there is no particular yield drop.
This is a very important process in that it allows the formation of the third electrode.

The solid-state display device manufactured by the method of the present invention applies voltage independently to each active element by passing it through red (referred to as R), green (referred to as G), and blue (referred to as B) filters. It can be added as a Y axis. Therefore, it has the feature of being able 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 pixel is the electrode 22 of the nonlinear element 2.
(second electrode) is connected to one electrode 23 (third electrode) of the liquid crystal 3. The non-linear element is connected to the address lines 4 and 5 of the X wiring that provides the clock signal.
are connected by an electrode 21. On the other hand, the fourth electrode 24 of the liquid crystal 3 is connected to the data lines 6 and 7 of the Y wiring. The Y wirings are provided correspondingly to the 20' side of another light-transmitting insulating substrate, typically a glass substrate (FIG. 4C). This fourth electrode 24 has R (red) Y ₁ , G (green) Y ₂ , B (blue) (Y ₃
It has filters 25 and 25' (not shown in the drawings), and is provided with 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 less likely to occur, and the resistance of this part should be set to 10 ⁹ Ω or more, preferably
It has become possible to increase the resistance to ¹⁰ Ω or more.

Such picture elements are arranged in a matrix, which is shown as 2×2 in the drawing. However, the present invention does not require such a small matrix, but a scaled-up display device, for example (100 x 100, 1920 x 200 or 512 pixels).
It is effective for large matrix panels such as

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-2 correspond to the longitudinal cross-sectional views of FIG. 4 C-C'. FIG. 2D-1 corresponds to the longitudinal sectional view taken along line A-A' in FIG. 4, and shows the device structure.

In FIG. 2A, Corning 7059 glass 20 was used as the light-transmitting insulating substrate. An aluminum film 11 as a conductive film and a chromium film 12 on top of the aluminum film 11 are formed on this upper surface by sputtering or electron beam evaporation.
They were formed to a thickness of 0.1-0.5 μ and 500-1500 Å, respectively. Chrome (500 to 1500) was added under the aluminum to further promote adhesion with the glass.
Å) may be formed.

After this, NIN (including NP ^- N, NIPIN, NIPI ^- IN) is applied to these entire surfaces using the plasma gas phase reaction method.
A composite diode made of a non-single crystal semiconductor structure was formed. In other words, N-type semiconductor is replaced with silane.
By performing high frequency glow discharge of 13.56MHz,
A non-single crystal semiconductor is created on the surface of the substrate maintained at 200 to 300°C.

Its electrical conductivity was 10 ⁻⁷ to 10 ⁻⁴ (Ωcm) ⁻¹ and the thickness was 500 to 2500 Å. Then 10 ^-6 ~
Sufficient vacuum was drawn to 10 ^-7 torr. Silane (SimH _2n+2 e.g. SiH ₄ with m=1) and DMS (Si
(CH ₃ ) ₃ ) and further added B ₂ H ₆ as needed to form an I-type non-single crystal semiconductor having a thickness of 300 Å to 0.5 μ. For example, DMS/
(DMS+SiH ₄ )=1/80 and B ₂ H ₆ /SiH ₄ =7PPM to form P ^- type SixC _1-x . Another 10 ^-6 ~
Sufficient vacuum was drawn to 10 ^-7 torr. An N-type semiconductor was laminated thereon to a thickness of 50 to 500 Å to form an NP ^- N junction SiSIxC _1-x (0<X<1)-Si heterojunction.

Thereafter, chromium 15 for light shielding was laminated as a second electrode on the upper surface by electron beam evaporation or sputtering.

Furthermore, as shown in FIGS. 2A and 2B, anisotropic plasma etching was performed using the first photomask 16 so that the peripheral portion 26 was vertical, thereby forming a laminate 17. Next, for example, 200℃ for these entire surfaces.
Thermal oxidation was performed on the semiconductor 2, and silicon oxide was produced by solid phase-vapor phase oxidation. Next, a photosensitive polyimide resin 29 was formed on the entire surface of these to a thickness of about 2 μm by a coating method. Thus, the upper surface 15 of the laminate 17 and the upper surface 39 of the polyimide resin 29
The laminate 17 was made to have approximately the same plane (the surface of the insulating material and the surface of the laminate are smoothly continuous) after curing except for the convex portions of the laminate 17. For example, when the thickness is reduced by 40 to 50% due to development and curing, the thickness of the laminate is approximately 1μ, so the thickness is set to approximately 2μ. Next, ultraviolet light 40 was exposed from the back side of the glass substrate 20 using a known mask aligner without using a mask. For example, Cobilt's aligners are approximately 2
Exposure was made for a minute. For ultraviolet light having an intensity of 300 to 400 nm wavelength (10 mW/cm ² ), 15 to 30 seconds is sufficient.

Then, as shown in FIG. 2C, the convex region above the stacked body having 26 side surfaces, which is in the shadow, is not exposed to light, but only the periphery of that side is exposed to light. After further development, the non-photosensitive convex portions were dissolved away using a rinsing solution. Thus, Figure 2C was obtained.

Next, do all of this at 180℃ for 30 minutes + 300℃ for 30 minutes +
The mixture was cured by heating at 400°C for 30 minutes in nitrogen.
In this way, in addition to exposing the second electrode of the nonlinear element, which is the upper surface of the laminate, without using a photomask, this upper surface and the surface of the polyimide resin insulator in the peripheral area can be made to be approximately on the same plane. It became possible.

Next, CTF was formed on the entire upper surface of FIG. 2C using ITO or tin oxide to a thickness of 0.1 to 0.5 μm. Furthermore, a second photomask is used to
I selectively etched the CTF. In addition to this CTF
23 constitutes the third electrode for the pixel of the liquid crystal (Fig. 1 23), and using this CTF as a mask, the electrode 3 between the pixels is
The unnecessary semiconductor of No. 1 was removed as shown in D-1.
In this way, Figure 2 D-1 and D-2 were obtained.

Furthermore, it is effective to fill and form a portion of the polyimide resin for forming an alignment film on the insulator CTF similar to 29 on the side surface of 31 of this semiconductor after this.

That is, in FIG. 2, a first electrode 21 on a glass substrate 20, a composite diode 2 made of an NP ^- N or NIN semiconductor stack, a second electrode 15, and a light-transmitting electrode closely attached to the second electrode. A third electrode 23 made of a conductive film was provided to cover the semiconductor stack 2 and the organic resin around the sides.

As a result, it was possible to obtain nonlinear characteristics as shown in FIG. 3 (electrode area 20 μ×420 μ) corresponding to FIG. 2 (the vertical axis shows the absolute value on a log scale).

Embodiment 2 The structure of the present invention is shown in FIG. 4, which shows a plan view A and longitudinal cross-sectional views B, C, and D of a region 1 surrounded by a broken line in FIG. 1.

Further, FIGS. 4B, C, and D show longitudinal cross-sectional views taken along lines A-A', B-B', and C-C' in A, respectively. In addition, FIG. 4C also shows the liquid crystal 3, the upper electrodes 6, 7, and the substrate 20', while the other parts A, B, and D show 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 first electrode 21, the leads 4 and 5 connected thereto, and the semiconductor 2 having the same shape thereon and the conductor constituting the second electrode 15 are formed with a width of 20 μm using the first mask.

That is, the electrode area of the nonlinear element is 20μ×420μ, and one of its electrical characteristics is shown in FIG.

Further, the side surfaces of the semiconductor and the lower first electrode are filled with an organic resin 29, and the upper surface of the organic resin 29 and the upper surface of the second electrode are configured to be approximately the same plane. Next, a CTF is formed over the entire surface of the laminate in close contact with the upper electrode 15. Using a second photomask, only the CTF pixels 23 and 23' were etched and removed (420μ×420μ).

Thus, the second electrode 22 of the pixel, the electrode 22' of the adjacent second pixel, and the lead 4 between them.
(FIG. 4B) were made to have the same width, and a self-aligned configuration could be achieved even with respect to pattern deviation in the lateral direction (horizontal direction in the drawing). In the vertical direction of the drawing, there is a second electrode 2 within the upper end and lower end of the 23 electrodes.
2 should be formed. Then, the semiconductor is removed from the opening groove 31 between the two semiconductors 22 and 22'.
Leads 4 and 5 are provided on the substrate 20 in close contact with each other. That is, since the two semiconductors 22 and 22' are isolated by the insulator 34 for the alignment film, the equivalent resistance 33 that hardly causes crosstalk is 10 ¹⁰
It could be removed as a substantially infinite value greater than Ω.

Furthermore, the other opposing fourth electrode 24, 2
4' 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,
A red filter is applied to this electrode 6, a green filter is applied to electrode 7, and a blue filter is applied to the adjacent electrode (not shown) using a known electrodeposition method or dyeing method.
formed. Thereafter, the polyimide 34', e.g.
This PIQ is coated with PIQ to form a protective film.
was subjected to orientation treatment.

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 the gap was evacuated, 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 fills the periphery of the side of a laminate having a width of only 20 μm with an organic resin of approximately the same height. Therefore, it has become possible to eliminate the problem in the process of peeling of the laminate due to the difference in thermal expansion with the glass substrate. Furthermore, the number of photomasks required to fabricate the substrate on the side with active elements is only two, and in addition, the electrode area of the nonlinear element (current value when applying a predetermined voltage)
It does not change even if it is shifted by up to ±200μ up or down from the center of the rectangular electrode, or even if it is shifted by several mm to the left or right, and it has constant nonlinear characteristics, and the electrical characteristics of active drive to the entire matrix We were able to prevent variations.

It is an alternating current drive system, and has the characteristic that it is easy to control gradations, especially since the threshold value of the diode can be controlled by the process conditions during stacking of semiconductor layers using a gas phase reaction method.

In the present invention, the nonlinear element is an NIN junction or a Si-SixC _1-x (0<X<1)-Si 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 devices having the origin symmetric characteristic shown in FIG. 3 using the -TO-BACK method, the MIM (metal-insulating film-metal) structure, and other Zener characteristics or avalanche characteristics.

[Brief explanation of the drawing]

FIG. 1 shows a circuit diagram of a liquid crystal display panel of the present invention. FIG. 2 is a group of longitudinal sectional views showing the manufacturing process of the present invention. FIG. 3 shows the operating characteristics of the nonlinear element of the composite diode of the present invention. FIG. 4 shows a plan view and a longitudinal sectional view of the display panel of the present invention.

Claims (1)

[Claims] 1. A method for manufacturing a solid-state display device in which a plurality of active element pixels are arranged in a matrix on a substrate, in which a first electrode, a nonlinear element, and a second electrode are laminated on a transparent substrate. a step of forming a laminate in a predetermined shape; a step of forming a photosensitive organic insulating film on the laminate and the substrate around the sides; and a step of irradiating light from the substrate side to A step of causing a photochemical reaction in the light irradiated area of the resin film, and exposing the second electrode by removing the organic resin in the non-light irradiated area, and an organic resin film on the electrode and around the laminate side. and a step of forming a third electrode in close contact with the second electrode and extending over the organic resin film. A method for manufacturing a semiconductor device. 2. A method for manufacturing a semiconductor device according to claim 1, wherein the photosensitive organic resin is made of a polyimide resin that is transparent to visible light.