JPH0652790B2 - Method for manufacturing solid-state display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION In the present invention, in a solid-state display device having a matrix structure, two insulating gate type semiconductor devices (hereinafter referred to as IGFs) are connected in parallel to one display pixel, and such a parallel structure is formed. When one of the IGFs is electrically defective, the defective IGF is trimmed (removal processing) to make it a non-operating element, and the purpose is to improve the manufacturing yield thereof.

The present invention separates the two IGFs from each other for this purpose,
One of the features of the IGF is that it is used as a non-operating element by irradiating a laser beam, and a pair of IGFs are used so that no damage will be caused to the other even if it is electrically separated from the lead (bus line).

The present invention provides, as a trimmable IGF, a first conductive electrode, a first semiconductor, a first insulator, a second semiconductor, a second conductive electrode, and a second conductive electrode on a transparent insulating substrate. Using a pair of two IGFs in which a channel forming region is constituted by a third semiconductor formed on the first insulator on the two sides of the laminated body formed by laminating six layers of the above-mentioned insulator Is. This relates to providing a solid-state display device in which IGFs having this paired configuration are connected to each picture element.

An object of the present invention is to provide a composite semiconductor device having such a matrix structure on a substrate and to provide a solid-state display device such as a liquid crystal display type or electrochromic display type display device.

In the case of providing a flat-type solid-state display device, there is known a liquid-crystal solid-state display device in which a pair of electrodes are provided on a parallel transparent substrate such as a glass or plastic plate and a liquid crystal is injected between the electrodes.

This liquid crystal display or electrochromic display element can be represented by a capacitor (hereinafter referred to as C) as its equivalent circuit. For this reason, FIG. 1 shows the IGF and C formed in a matrix of 2 × 2, for example.

In FIG. 1, each address of the matrix constitutes one picture element by two IGFs (10) and (10 ') forming a pair and C (70) as a display section.

These are connected to the bit lines as columns (leads in the Y direction) (51) and (52), while rows (X) are connected as gate branches.
Direction read) (53), (54) (word lines) are provided.

Then, for example, if (51) and (54) are set to "1" and (52) and (54) are set to "0", both IGFs (10) and (10 ') are turned on, and IGFs at other addresses are Turns off. Then, select any one bit line and word line and turn them on,
The display section indicated by the electrical equivalent element C (70) can be selectively turned on.

According to the present invention, when the active picture elements in the solid-state display device are, for example, 640 × 525, it is impossible to operate the IGFs of all the picture elements normally in consideration of the product yield. Therefore, according to the present invention, when the gate of one of the pair of IGFs is damaged (short),
Each pixel is provided with a so-called redundant element, which is a non-defective by irradiating the damaged IGF with laser light or by applying an electrical pulse to vaporize and remove one of the shorted electrodes. It is a thing. In addition to this IGF
For the gate electrode of the above, a sublimable metal is used for LT, especially a metal containing chromium as a main component, and the electrode in the X direction does not hinder even if this electrode is LT. Is featured.

In addition, the second conductive film is the electrode of the IGF, and the lead wire for the bit line is used as it is, and the second conductive film and the insulator of the laminated body can be simultaneously formed in the same stack.
It was possible to form the matrix structure only four times of photolithography (three times if the word line lead and the gate electrode are made of the same material).

Thus, by combining the present invention on the basis of its design specifications, a solid-state display device for a flat screen television, which replaces the cathode ray tube, could be manufactured.

FIG. 2 is a partial sectional view of a perspective view of the solid-state display device of the present invention. In the drawing, a glass or plastic translucent insulating substrate (1), a lower electrode (36) of a pixel, and a laminated body (60) (the lead in the Y direction is partially formed by the second conductive film (16). (Provided), two leads (29) in the X direction, and two IGF gate electrodes (19) forming a pair extending from each of them.
(19 '), alignment treatment coatings (30, 32), liquid crystal (70), upper electrode (33) of display element, upper ground electrode (34) of glass or plastic, and deflector (35). The laminated IGF on the insulating substrate (1) in such a solid-state display device is enlarged to show the solid-state display device of the present invention below.

FIG. 3 shows a longitudinal sectional view of a laminated IGF for carrying out the present invention and a manufacturing process thereof.

This drawing shows a manufacturing example in which two IGFs are used for driving the display pixels and these are manufactured along one laminated body, but the same is true when a plurality of IGFs are manufactured on the same substrate.

In FIG. 3 (A), the first conductive film (2) was provided on the insulating substrate (1) such as a quartz glass or borosilicate glass substrate or an organic film as the lower electrode and one electrode of the pixel. In this embodiment, a translucent conductive film containing fluorine-containing tin oxide as a main component is formed to a thickness of 0.3 μm. This was subjected to selective etching using the first mask. Furthermore, a first non-single crystal semiconductor (3) having P or N type conductivity is provided on the upper surface of 100 to 3000 Å, and a first insulator (4) (0.3 to
3 μ), and a second semiconductor (5) (0.1 to 0.5 μ) having the same conductivity type as the first non-single-crystal semiconductor (3) was provided by stacking. This stack has a NIN, PIP structure (I is an insulator).

On top of this, ITO (Indium tin oxide), MoSi ₂ , T
The _second heat-resistant metal mainly composed of iSi ₂ , WSi ₂ , W, Ti, Mo, Cr
The conductive film (6) was made of metal (500 to 3000 Å), which was in close contact with the semiconductor and had chromium as a main component, and aluminum was laminated on the upper surface of 0.5 to 2 μ, for example, 1 μ. Further, a second insulator (7) effective as an interlayer insulator is laminated on the upper layer to a thickness of 0.5 to 5 μm, for example 1 μm. This insulator is an organic resin such as a silicon oxide film, a silicon nitride film or PIQ formed by the LP CVD method, the PCVD method or the photo CVD method.

Next, an unnecessary portion of this laminated body (60) was removed using a second photomask.

N, P of the first non-single crystal semiconductor (3) and the second semiconductor (5)
It was effective to lower the contact resistance between P or N and the first and second electrodes as N ⁺ NINN ⁺ , P ⁺ PIPP ⁺ (I is an insulator) as a layer N ⁺ N or P ⁺ P.

As described above, the first conductor (2), the first non-single-crystal semiconductor (3), the first insulator (4) shown in FIG.
Second semiconductor (5), second conductor (6) and second insulator (7)
The laminated body including the
As shown in FIG. 1B, the first conductor (12), the first non-single-crystal semiconductor (13), the first insulator (14), the second semiconductor (15),
A laminate (6 comprising the second conductor (16) and the second insulator (17)
0) was formed by using the second photomask.

Here a plasma vapor etch such as HF gas or CF ₄ + O ₂
Etching rate is 0.1-0.5 torr, 30W using mixed gas
It was set at 500Å / min.

After that, the first non-single-crystal semiconductor (13), the first insulator (14), the second semiconductor (15), and the second semiconductor (13) that form these stacked bodies (60) are formed.
Intrinsic or P ⁻ or N ⁻ -type non-single-crystal semiconductor which constitutes the channel forming region and covers the conductor (16) and the second insulator (17) was laminated as the third semiconductor (24). This third semiconductor (24) is a silane glow discharge method (PCVD method) on a substrate,
Room temperature to 500 ℃ using photo CVD method, LT CVD method (also called HOMOCVD method), for example 200 ℃ in PCVD method, 0.1 torr,
It is provided under the condition of 30W, 13.56MHz and uses non-single crystal silicon semiconductor of amorphous or semi-amorphous (semi-amorphous) or polycrystalline structure to which hydrogen or fluorine is added. . In the present invention, an amorphous or semi-amorphous semiconductor is mainly shown.

Furthermore, a third semiconductor (24) is placed on the top of the same reactor in the same reactor.
Optical CV of the silicon nitride film (25) without exposing the surface to the atmosphere
Produced by vapor-phase reaction of silane (disilane may be used) and ammonia by mercury excitation method by method D, and thickness is 300 to 2000Å
And

This insulating film is 100% in a nitrogen or ammonia atmosphere activated by electromagnetic energy with a frequency of 13.56MHz to 2.45GHz.
It may be immersed at ˜400 ° C. to form a solid-vapor reaction silicon nitride.

Alternatively, silicon nitride may be formed by the PCVD method.

Thus, around the side of the first insulator (14) as shown in FIG. 3 (B), the channel forming regions (9), (9 ') and the insulator as the gate insulator (25) thereon are formed. Let The third semiconductor (24) is the first non-single final semiconductor (13) and the second semiconductor (1).
The diode junction is formed with 5).

In FIG. 3 (B), a third conductive film (18) is then formed on the laminated body so as to have a thickness of 200 to 2000Å, for example, 500Å.

This conductive film (18) is a transparent conductive film such as ITO (indium tin oxide), tin oxide, or indium oxide, Si, M.
A heat-resistant and sublimable conductive film containing o and Cr as main components was used.

Here, ITO (500Å) or a metal whose main component is chromium
(300-800Å) with 1 layer film or 2 layer film (20), (21).

Furthermore, aluminum is 0.5-3μ on this upper surface, for example 1.5
The sheet resistance is laminated by vacuum deposition to a thickness of μ.
0.1Ω / □ or less.

After that, a resist is formed on this upper surface, and the word line (X direction) (5) shown in FIG.
The aluminum for 3) was etched. Furthermore, the fourth
Gate electrodes (19) and (19 ') were formed by the etching method using the mask of FIG.

Thus, FIG. 3 (C) was obtained. Of course, if the word line (51) and the gate electrode are used together, this mask is processed in the same manner as.

As is apparent from FIG. 3 (C), the two IGFs (10), (10 ') have channels (9), using both sides of the laminate (60).
(9 ') and two, and has a source or drain composed of the first non-single-crystal semiconductor (13) and a drain or source composed of the second semiconductor (15). Electrode (1
9) and (19 ') are formed, and the gate electrodes of each IGF are separated from each other by a width of 20 to 40 µ.

Thus, the source or drain is the first non-single-crystal semiconductor
(13), a channel forming region (9), a third semiconductor (24) having (9 '), a drain or a source are formed by the second semiconductor (15), and a gate insulator is formed on the side surface of the channel forming region.
(25), IGFs (10), (10 ') of the laminated type, which form a pair with the gate electrodes (19), (19') provided on the outer surface thereof, could be manufactured.

In the case of investigating the operating characteristics of the two IGFs, it is assumed that one of the gate electrode sources or drains is short-circuited. Or gate electrodes (19), (19 ')
Since the conductive electrode composed of the first conductor (2) and the electrode (12) of the element which constitute the picture element are one electrode (36) of the capacitor, the charge accumulated for a certain period of time during the driving operation is This must be maintained, and if a short circuit occurs, this charge cannot be retained.

In such a faulty IGF, a current of 100 nA or more (each IGF has a channel length of 1 μ and a channel width of 2 mm) flows between the X-direction lead and the Y-direction lead of the IGF drive operation. For the detection of this defective cell, light irradiation (wavelength of 500 nm or less is preferable) was performed from the substrate side, and it was possible to detect it by the magnitude of photocurrent of carriers generated by this light irradiation. That is, if the product was a good product, it was greatly affected by the photocurrent.

Of course, in the present invention, the lead in the X direction uses aluminum as the main wiring. The sheet resistance is also 0.1Ω / □ or less, and the thickness is 0.5μ or less. On the other hand, however, the IGF gate electrode branched from this lead is made of ITO only, ITO and a metal containing chromium as a main component or only a metal containing chromium as a main component, and has a thin thickness (for example, 300 to 800Å).
The use of the sublimable conductor is a major feature.

That is, when the sublimable metal is used as the gate electrode and the thickness thereof is thin, the pulse voltage is applied to the lead in the X direction and the Y direction.
It was applied at a high voltage so that a good gate insulating material was not damaged between the leads in the direction. Then, only the short-circuited defective IGF gate portion generates heat, and the electrode on the gate portion can be partially sublimated and removed.

At this time, it is not preferable for the gate electrode to be a metal (gold or the like) that is likely to react with an insulator such as aluminum to form a lower oxide or diffuse easily into the insulating film. Therefore, the gate electrode used in the present invention is X
It is branched from the direction lead, and the direction is vertical.

If one of the paired IGFs is defective, the gate electrode is simply trimmed by applying a pulse voltage and removed. Alternatively, there are two methods of removing the gate electrode from the REIT by laser trimming.
It was possible to apply it to all defective IGFs in the matrix pixel of × 525 and drive it as a good product.

Of course, as a trimming process, in order to check the IGF of the defective portion, an electric pulse is first applied to damage the gate electrode, and then this gate electrode is visually detected and
It goes without saying that it is also effective to trim the IGF from the lead by laser light to make it inoperative.

FIG. 4 is a plan view of a portion of the solid-state display device of the present invention shown in FIG. 1 using the IGF shown in FIG.

FIG. 4 (A) corresponds to the addresses (1,1), (1,2), (2,1), (2,2) in FIG. 1 and especially the IGF at the address (1,2). FIG. Further, FIG. 4 (B) is a vertical sectional view taken along the line BB 'in FIG. 4 (A). Further, FIG. 3 (C) corresponds to the vertical sectional view taken along the line AA ′ in FIG. 4 (A). The lower electrode of this IGF (12)
More extended electrode (provided on the lower side in FIG. 4)
(36) is connected to a liquid crystal (capacitor) (70) composed of picture elements. The other is provided as the ground electrode (32) of the liquid crystal (70).

In FIG. 4, a gate electrode (19), (19 ') provided along the laminated body (60) is provided in the X direction lead (53) orthogonal to the laminated body (60). ). The second conductive film (51) provided inside the laminate (60) is
It was configured as lead wiring in the Y direction. Thus the X direction,
It has a matrix structure in the Y direction and can have a 1Tr / pixel structure.

Further, as is clear from FIG. 4, the manufacture of this display could be obtained by photoetching five times (three times for the element alone). Conventionally, the number of times was used seven times, but the number of times can be reduced by two in the configuration of the present invention. Also, the area required for the IGF of the display of the present invention is 1% of the whole.
It is the following.

The display portion was 91% and the lead portion was 8%. According to the present invention, when a large 20-inch display is manufactured, the minimum mask line width becomes 25 μ by the current mask manufacturing technology.
However, the present invention has a great feature that the channel length of this IGF is 1 μm or less and the mask precision is not limited at all, while using 25 μm as a lead in the X and Y directions. And since it is an IGF with a short channel length,
It has other features that the area required for the IGF on the substrate can be reduced and the accuracy of photolithography does not limit the upper limit of the operating frequency.

Furthermore for operating these picture elements at a high frequency, the frequency characteristics of the IGF is critical, IGF the present invention is V _DD
= 5V, _GG = 5V, cutoff frequency 10MHz or more (17.5M
Hz) (N-channel IGF). V _th
= 0.2 to 2V can be achieved by controlling the concentration of the impurity added to the gate insulator (25).

In this way, when one of the gate electrodes of the IGF forming a pair is short-circuited, the laser from above this, for example, Q
By irradiating a switched YAG laser beam to sublimate and vaporize the gate electrode, the yield of the whole panel is 40% from that of the previous 3% (defective pixels are 5 or less). The yield could be improved to exceed%. In addition, it has a laser beam (here, a YAG laser having a wavelength of 1.06μ is used) or a diameter of 10 to 30μ. However, the gap between the pair of IGF gate electrodes of the present invention is 30
Since they were separated by μ, there was no hindrance to the other IGF paired, and the picture element on the shorted side on one side could be removed.

In addition, the number of masks required for manufacturing is four, and many features such as mask accuracy are not required.
In addition to being able to make it extremely short to 1 μ, it was possible to make it possible.

After further processing these triminds, this
The IGF overcoat polyimide resin (26) fills the liquid crystal (70) only in the pixel area. The peripheral part of the picture element also serves as a spacer (thickness 1 to 10 μ) between the two electrodes (36) and (33) (see FIG. 2). It was blackened (no reflection) and used as a black matrix. By making this black matrix, the contrast of this picture element could be improved. Furthermore, in the area of (31), a display object such as GH
This guest element is filled with liquid crystal such as (guest / host) type.
The control was performed by turning on and off the IGF (10) and (10 ').

In the present invention, the distance between the two electrodes (30) and (32) that have been subjected to the alignment treatment for the liquid crystal (31) is set to 1 to 10 μ, and a gap such as GH
Inject liquid crystal into the mold, and add red, green, and
This display can be displayed in color by incorporating a yellow filter. Then, the three elements of red, green, and yellow may be arranged alternately.

In the present invention, it is effective to use a semiconductor as the second stacked body and use the periphery of this side as a channel formation region. However, although such a structure has a feature that there is no step of forming a third semiconductor, in such a case, since the surface of this semiconductor is exposed to an etching atmosphere, the method using the third semiconductor having the above interface state density is It has a disadvantage that it becomes larger than the above and variation occurs between each IGF.

Silicon, germanium or silicon carbide (SixC _1-x 0 <x <1) was used as the non-single crystal semiconductor in the present invention, and silicon carbide or silicon nitride was used as the insulator.

[Brief description of drawings]

FIG. 1 shows an equivalent circuit of a matrix structure in which an insulating gate type semiconductor device of a solid-state display device of the present invention and a capacitor are picture elements. FIG. 2 is a perspective view of the solid state display device of the present invention. 3 (A), (B), and (C) are vertical cross-sectional views showing the steps of the laminated insulating gate type semiconductor device of the present invention. 4 (A) and 4 (B) are vertical sectional views of a solid-state display device showing a flat display in which the laminated insulating gate type semiconductor device of the present invention and a capacitor or a display unit are integrated.

Claims (2)

[Claims] 1. A pair of first and second insulated gate field effect semiconductor devices, in which a source or a drain is connected to a first electrode constituting a pixel made of a conductive film, are provided on a substrate, and the semiconductor device is provided. The drain or source of the semiconductor device is connected to a lead in the Y direction, and the gate electrodes of the semiconductor device having a sublimable metal as a main component are spaced apart from each other and connected to the lead in the X direction. A method for manufacturing a solid-state display device, characterized in that a damaged gate electrode of a pair of insulating gate type field effect semiconductor devices is vaporized and removed. 2. A method for manufacturing a solid-state display device according to claim 1, wherein the sublimable metal is a metal whose main component is chromium.