JPS59109088A - Solid video display unit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a solid-state image display device capable of displaying high-resolution color images.

Cathode Ray Tube (Cathode Ray Tube)
Development of solid-state video display devices to replace cathode ray tubes is currently underway. As a light-emitting element for displaying images, 7 LEDs (L
light emitting diode (56 photodiode) is attracting attention.

First, FIG. 1 shows the basic structure diagram a and the energy band diagram of an LED.

In FIG. 1a, Ga1-XAIXAS (D p region 102 and G
a, -yAlyAS (7) shows the cross-sectional structure of an LED consisting of a double heterostructure of n-region 103 (consisting of two heterojunctions 104, 105). Here, the electrons injected through the p-n heterojunction 1o6 recombine with holes in the p-region 101 of the GLAS, and the electrons are biased by the power source E and have a wavelength corresponding to the bandgap energy of GaAs. It emits light. At this time, as can be seen from FIG. 1, the injected electrons are exposed to Ga 1-
The light is not diffused into the p-region 102 of GaAs, and the light is emitted only from the p-region of GaAs.

If such LEDs are arranged two-dimensionally on the surface of a semiconductor substrate, it will be possible to display a two-dimensional image in black and white.
When trying to display a color image, the three primary colors R (red) are applied to each pixel of the color image.

Three light emitting elements that emit light in G (green) and B (blue) are required. Therefore, if you try to obtain the same resolution for black and white video display as color video display, the number of light emitting elements must be 3.
The problem arises that it has to be doubled.

OBJECT OF THE INVENTION The present invention solves the above-mentioned problems of the conventional art, and can easily be realized by creating a three-dimensional structure in which a plurality of electro-optical conversion parts (light-emitting element regions) are formed corresponding to one pixel region. An object of the present invention is to provide a solid-state video display device capable of realizing high-resolution color video display.

Structure of the Invention The solid-state image display device of the present invention is characterized in that: (i) the direction perpendicular to the substrate (
(1) A plurality of resistive gate electrodes (hereinafter referred to as RG electrodes) embedded in the substrate to etch the electro-optic converter in each layer (thickness direction); (abbreviated)), which enables high-resolution color image display.
Embodiments Before describing the present invention in detail, the operating principles of the basic components of the present invention will be explained.

Let's consider the electric light conversion section.

Generally, p-n junction LE＼D(7) spectral sensitivity characteristic R(λ
)I/'i, However, Bandgap energy h/l of Eg2 full emission region semiconductor material η(λ): Effective quantum efficiency ■(λG-included)-1(λ≦λG) −〇 (λ〉λc, ) and V=. In the semiconductor heterojunction of Egl> Egz (
1) Applying the formula, it becomes as follows.

However, U(λG1-λ)=1 (λ≦λc+)=0
(λ>λc, 1) U(λG2−λ)=1 (λ≦λG2 )=○ (
λ>λG2) Therefore, in the case of ・Eg+>8g2, λc+<λG2, so U(λG1−λCZ) is 30. This means that the 6 semiconductor having Egl becomes transparent by 7 dimensions to the light emitted within the semiconductor having 8g2. This is generally called the window effect. This is R (red,
(R)≠600~7001m), G (green, λ(C)
-j600~600nm), B (blue, λ(B)≠4o
○~500nm) in the substrate thickness direction,
From the surface, it means a blue light emitting region, a green light emitting region, a red light emitting region and a surface C.

Next, a resistive gate (RG) electrode used as a scanning means of the electro-optic converter will be considered.

The basic structure of a resistive gate electrode is shown in FIG. 2a.

A Re electrode 204 is formed on an n-region 202 formed on a p-substrate 201 via an insulator 203, and a voltage E is applied between terminals X and Y at both ends, as shown in FIG. The potential distribution of the zn-region 202 is obtained. At this time, if the depletion potential ψ of the n-region 202 is set to ψ-ψ0, the range indicated by A does not correspond to the depletion region /S.

In order to realize the scanning function using such Re electrodes, it is sufficient to have at least two Re electrodes, as shown in FIG. 3 iaK.

FIGS. 3a and 3b show a top view and a cross-sectional view of the Re electrode, respectively, and FIG. 3C shows its potential distribution.

Re electrodes 304 and 305 are formed on an n-region 302 formed on a p-substrate 301 with an insulator 303 in between. When voltage E1 is applied between terminals B and C at both ends of Re electrode 304, the potential distribution becomes ψ1, and R(
When a voltage E2 is applied between terminals -E at both ends of the electrode 306A, the potential distribution becomes ψ2.

At this time, if the depletion potential of the gi region 302 is ψ-ψ0, the range indicated by F becomes the depletion region for the Re electrode 304, and the range indicated by G becomes the depletion region for the Re electrode 305. It becomes an area of transformation.

As a result, the direction perpendicular to the Re electrodes 304 and 305 (the third
If you look at the n-region 302 in the direction perpendicular to the plane of the drawing (in the direction perpendicular to the plane of the drawing), a channel is formed in the range indicated by H that crosses the two Re electrodes 304 and 306. To scan to the right, sawtooth waves R1 and R2 may be supplied between the B-1 terminal and the D-E terminal via capacitors, respectively.

The electro-optical converter as described above and a plurality of R as scanning means
(A solid-state image display device according to an embodiment of the present invention, which is configured with electrodes and electrodes, will be described with reference to the drawings.

First, FIG. 4 shows a portion corresponding to a basic pixel area of a solid-state video display device according to a first embodiment of the present invention, and its element structure and operation will be explained.

FIG. 4a shows a top view thereof, FIG. 4A shows a sectional view taken along the line XX', and FIG. 4C shows a sectional view taken along the YY' line of FIG. 4A.

This basic pixel area is a continuous part in the Y-Y' force direction (
(eg, in+ region), the solid-state image display element is constructed by arranging units corresponding to a plurality of pixels in the Y-Y' force direction and arranging them in the XX' force direction.

The configuration in FIG. 4 has an insulator 402 on a p-substrate 401
An n region 4o3 (this is used as a signal transmission line) separated in the x' force direction and a p region 404 formed on the n region 403 (n type R (electrodes 405 and 406 are present continuously in the Y-Y' force direction, which is used as a scanning means), and an insulator 407 is placed on top of this p region 404 to separate the x-, x' force directions and the Y- n region 40 formed separately in the Y' force direction
8 and p region 4o9 (this p region 409 becomes a light emitting region) and 1. p region 410 formed on p region 409
Toni J:! ll is formed. With this configuration, n area 4
A bias voltage E is applied between 03 and p region 410. Further, the portion between the n region 403 and the p region 4101 is called an R section. In addition, ERoun 401 and n area 4
This is a voltage for applying a reverse bias to 03.

Further, an n region 411 and a p region 41 are formed on the p region 410.
2 is formed, and an insulator 413 is formed on the p region 412.
An n-region 414 (used as a signal transmission line) separated in the -x' force direction is formed.

N region 411 and p region 412 are provided to separate p region 410 and n region 414, and their function is to
Reverse Bahian town pressure ER between area 410 and n area 411
This is realized by a reverse bias voltage EGO between O' and p region 412 and n region 414.

Further, on the n region 414, a p region 415 (an n-type R buried vertically in this p region 415) is formed.
16,417 exist continuously in the Y-Y' force direction. (this is used as a scanning means), a 7vn region 419 and a p region 42.
0 (this p region 420 becomes a light emitting region) and an n region 421 formed on the p region 420.
A bias voltage E is applied between region 414 and n region 421.

Moreover, the part from the n area 414 to the n area 421 reed is called the G section.

Furthermore, -F of the n area 421, the n area 422. and n
A region 423 is formed, and an insulator 42 is formed on the n region 423.
4, an n region 425 (used as a signal transmission line) separated in the x-x' force direction is formed.

N-region 422 and n-region 423 are provided to separate n-region 421 and n-region 425, and their functions are to reverse bias voltage Ear between n-region 421 and n-region 422; This is realized by a reverse bias voltage EBo between the region 423 and the n region 425.

Furthermore, an n region 426 formed on the n region 425 (embedded vertically within this n region 426, ftn type RG electrodes 427+428 exist continuously in the Y-Y' force direction.This is used as a scanning means. n region 430 and n region 431 (
This n area 431 becomes a light emitting area) and n area 431
A bias voltage EB is applied between the n region 425 and the n region 432. ′! In addition, from the n area 425 to the n area 432''i
The part at is called the B section.

Finally, a protective transparent glass 433 is formed on the n-region 432 to form the basic structure of the unit pixel.

A unit pixel as shown in Fig. 4 is in section B in the thickness direction.

It consists of a G section and an R section, which correspond to the three primary colors B, G, and H in the case of color video display. For example, the emission wavelength in section B is 400~soo
nm, the emission wavelength in the G section is 500 to 6oOnm, R
The emission wavelength of the section is 60o~7Q.

When assigning nm, the width of the emission wavelength is narrow in the LED with the structure shown in Fig.
nal grading) and when it is better to use the structure. This also helps to obtain a clean heterojunction interface. As shown in FIG. 6, the -n+ substrate 501 and the V region 502 are made of InP, and the n region 603 is made of InzGal.
-XASYPI-Y, the mixing gradient is n region 50
4,505, In)(GaI-xAsyP
In the region represented by j-y, where it touches InP, X=
It is made with a gradient of molar ratio so that y=Q and ux=X+y=Y at the place where it touches InxGa1XASYpj-y.

The gradient can be created by changing the parameters x and y continuously or in small steps.

When this result is applied to the n-region 101 in FIG. 1, Eg changes gradually, so it is possible to narrow the width of the emission wavelength by 6
Becomes Ding Noh.

This is the p region 4o9°420 which is the light emitting region in FIG.
．． By applying this to 431, the necessary width of the emission wavelength can be set.

Before giving a detailed explanation of the structure shown in FIG. 4, the operation will be explained. In the lR section, n is applied to the RG electrodes 405 and 406.
When a voltage sufficient to deplete region 404 is applied, a charge transfer channel 434 is formed in n-region 404 . As a result, electrons from the n-region 403 reach the n-region 408 via the transfer channel 434, and the electrons reach the n-region 409.
It recombines with holes and emits light.

Similarly, in the G section, n is applied to RG electrodes 416 and 417.
When a voltage sufficient to deplete region 416 is applied, a charge transfer channel 436 is formed in n-region 415 . As a result, electrons from the n-region 414 reach the n-region 419 via the transfer channel 435, and the electrons reach the n-region 420.
It recombines with the iih hole and emits light.

Similarly, in the B section, the RG electrodes 427 and 428 are
When a voltage sufficient to deplete region 426 is applied, a charge transfer channel 436 is formed within n-region 426 . As a result, electrons from the n-region 425 reach the n-region 430 via the transfer channel 436, and the electrons reach the n-region 431.
It recombines with holes and emits light. The above operation is performed in the R section,
It can be performed independently in G section and B section.

Next, a detailed explanation regarding the structure of FIG. 4 will be given.

Although the emission wavelengths in each section of R, G, and B in FIG. 4 have already been shown, they will be described again.

Since the emission wavelength width can be realized by the mixing gradient mentioned above, here, in order to determine the semiconductor that forms each region,
Consider typical wavelengths for each section.

Therefore, the following representative wavelengths λ(B), λ(G), λ(B
)think of.

FIG. 6 is a diagram showing the relationship between E and lattice constant of a multi-element compound of the l1l-V group.

From this FIG. 6, it is possible to make the lattice constants uniform in compound semiconductors corresponding to the above-mentioned λ(G) and λ(B). The more uniform the lattice constants are, the better the interface properties will be, and the more ideal the device properties will be.

For example, λ(B) has ALP)(Sb+-x, λ((-
) is (, ayAl + -yAs, λ(R) is G
ay'A11-y'As(y':) y ) may be used. Here, the p region 43 corresponds to λ(B).
1, the p region 420 corresponds to λ(G), and the p region 409 corresponds to λG). Other areas in section B are A
IPx'Sb1-x' (consisting of x' (x)).

The other regions of the G section are GazAll -2As (Z <
'! ). Other areas in R section are GayAl
, -yAs. For actual manufacturing, M
B E (Mo1ecular Beam Epitax
y) epitaxial crystal growth technology may be used.

Although it is possible to set Eg using the above-mentioned compound semiconductor, there is a slight deviation due to impurity doping.
[It is Noh.

For example, the above-mentioned AIPxSb4. , x and GayAl
+ - To make yAS etc. n-type, Li, Ss,
Te, etc. are used, and Zn, Cd, etc. are used to make it p-type.

At this time, when the impurity doping becomes high, a state of degenerate doping or impurity tail b can be realized as shown in FIG. Degenerate doping can be used as a correction to make the doping thicker and the impurity tail smaller by 1Kg.I was considering a configuration using a multi-component compound of the m-v group, but it is possible to use a multi-component compound of the 1l-Vl group. It is also possible to use

FIG. 8 shows the relationship between Eg and lattice constant of I-VI group multicomponents.

From the 8th □□□, λ(B) contains ZnzCd 1-xSy
Znx'(3d1-x's
y'T6+-y'(x'(x,'!'＜'! )
, ZnzCd 1-2Te may be used for λ(R). However, as the crystal structure changes from zincblende to wurtzite as the molar ratio gradient increases, it is heavier to make using a mixing gradient.

Next, the equivalent circuit shown in FIG. 9 will be explained.・Figure 9a
is the same as in Figure 4 (reverse bias power supply is omitted)
Then, the bias voltage (e.g. EB) and the signal voltage (e.g. e
B) is superimposed. FIG. 9 is an equivalent circuit corresponding to the 9th Na.

In FIG. 9, the light emitting diode DB1 p region 43
2+ corresponds to p region 431 + n region 430, and light emitting diode DC,1 has p region 421 + p region 42
0.corresponding to the n region 419, the light emitting diode DR1 corresponds to the p region 410. p region 409. Corresponds to n area 408.

Dimensions, RG Electric QGB1. GB′1 corresponds to n+ regions 428, 427, respectively, RG electrode eG1゜GG′1 corresponds to n+ regions 417, 416, respectively, and R(, electrode 1
GR1 and GR'1 are each n+, area ゜4o6゜40
Corresponds to 5.

Further, the signal line LB1 corresponds to the n region 425, and the signal line L
Corresponding to the G1ban region 414, the signal line LR1ban region 4
Corresponds to 03.

FIG. 1o shows an actual example of a solid-state image display device with one horizontal strip using one circuit of FIG. 9.

In FIG. 10, the unit pixels of FIG. 9 are arranged in a matrix of Km columns in the horizontal direction and n rows in the vertical direction.

RG electrode GB1. GB'1 is used to scan m light emitting diodes DB11 to DB1m arranged in the horizontal direction. RG electrode GG1. GG'1 is used to scan DGlm from m light emitting diodes DG11 arranged in the horizontal direction. Similarly, the RG electrodes GRl and GR'1 are used to scan the light emitting diodes DR11 to DHlm arranged in the horizontal direction m (li>1).

Note that R(, electrode GB1.GG1.GR1 is connected to terminal A1.
Commonly connected to A1', RC! Electrode GB'1. CG'1
゜GR'1 is commonly connected to terminals B1+B1/.

Furthermore, terminal A1. A voltage F1 is applied between A1' and a sawtooth wave Flat is applied through the capacitor, and a voltage E2 is applied between terminals B and B1' and a sawtooth wave RO2 is applied through the capacitor. The light emitting diodes DB11 to DB1m are scanned in the horizontal direction and emit light at the signal voltage "B1" supplied to the signal line LB1.Similarly, the light emitting diodes DG11 to DGlln emit light at the signal voltage ea1 supplied to the signal line LG1. The light emitting diodes DR11 to DR*m emit light with the signal voltage "IN" supplied to the signal line LR1.

These are arranged in n rows of RG electrodes (A+ r A1') ~
(An +An') and (B1.B1') ~ (Bn
, Bn') at the same time, all signal lines (LB1
~LBn)・(LG1~LGn), (LR1~LRn)
The light emitting diodes can be made to emit light simultaneously in parallel.

As described above, according to the present device, it is possible to realize a two-dimensional solid-state image display device capable of emitting light of a plurality of colors necessary for color reproduction from an electro-optical conversion section in one pixel area.

``In addition, this device has been explained using an actual example in which three electro-optic converters are provided in the thickness direction, but depending on the application, the number of electro-optic converters in the thickness direction can be increased to finely divide the emission wavelengths and allocate them. It's okay.

Furthermore, it goes without saying that it may be used as a three-dimensional image display element without changing the emission wavelengths of the electro-optic converters arranged in the thickness direction.

Effects of the Invention As described above, the solid-state image display device of the present invention has a three-dimensional structure in which one pixel for displaying color images has a plurality of electro-optic converters formed in the thickness direction of the substrate. This makes it possible to display multiple colors of light. As a result, the following effects can be obtained.

■ It is possible to display color images with higher resolution than with two-dimensional structured image display devices.

■ Although it has a three-dimensional structure, it can also be used as a three-dimensional image display device.

(2) In addition, since a combination of RG electrodes is used as the scanning means of the electro-optical conversion section, a high-frequency clock pulse is not required for horizontal scanning, and the driving method is simple.

(2) Similarly, since each row can be scanned simultaneously in parallel, it can be used as a display device for high-speed processing systems.

The following 'F' cannot be obtained with conventional video display devices.
/-1, which has great practical effects.

[Brief explanation of the drawing]

Figures 1a and b are cross-sectional views and energy band diagrams of a light-emitting diode using a conventional compound semiconductor; Figures 2a and t) are cross-sectional views and potential distribution diagrams of a basic resistive gate electrode; Figure a+ 1)+ Top view, cross-sectional view, and potential distribution diagram of a scanning circuit using two resistive gate electrodes, Figure 4 a+ J
O is a top view of a unit display unit constituting a solid-state image display device in an embodiment of the present invention;
Figure 5 is a cross-sectional view of a heterojunction with a mixing gradient, Figure 6 is a characteristic diagram showing the relationship between band gap energy and lattice constant for n+-V group compound semiconductors, Figure γ is a
Figure 8 shows the relationship between bandgap energy and lattice constant for II-Vl group compound semiconductors. 9a and 9b are a unit pixel structure diagram and an equivalent circuit diagram of the same device, and FIG. 10 is a plan view of a solid-state image display device constructed by arranging the unit pixels of FIG. 2 in rows and columns. . 431.420,409...p which is a light emitting region
Q'th-i, 426. 414. 403-(,Tj
Line n area, 4281427.4171 416
, 406゜405... Name of the agent for the n+ region which is the resistive gate electrode Patent attorney Toshio Nakao and one other person Figure 2 Figure 3 Figure 4 (α) Y B Fh -EG; "R. Figure 5 Figure 6 Tsuba j Teiaki [A1-kaidai 8 N Go 1 fixed number] Figure 9 (O-)

Claims (1)

[Claims] (1) Pixel areas allocated in rows and columns on the surface of a semiconductor substrate are arranged vertically on the substrate. A solid-state video display device comprising a plurality of electro-optical converters formed in a direction (thickness direction) K, scanning means corresponding to the electro-optical converters, and signal transmission means. Business) If the electro-optic converter is formed of a multi-component compound semiconductor, and the band gap energies of the multi-component compound semiconductors corresponding to the electro-optic converters arranged in the thickness direction are different, 1+! The solid-state image display device according to claim 1, characterized in that: (3) The scanning means is embedded in a signal charge transfer channel formed in the thickness direction inside the substrate between the electro-optical conversion section and the signal transmission means corresponding to each of the electro-optical conversion sections, separated into upper and lower parts. , and the electro-optical conversion section is composed of a plurality of resistive gate electrodes that are continuous in a scanning direction parallel to the substrate surface 1
The all-in-one image display device according to claim 1, characterized in that it weighs 2 loaves. (4) A patent claim characterized in that the resistive gate electrode is formed of a semiconductor material having a bandgap value larger than the value of the bandgap energy of the semi-non-n body (2-n body) constituting the electro-optical conversion section. (5) The solid-state image display device according to claim 1, wherein the signal transmission means is constituted by a signal line continuous in the direction of scanning the electro-optic converter. Video display device. (6) The signal line is formed of a semi-central material having a value that matches the bandgap energy of the semiconductor material constituting the electro-optical conversion section. The same-body image display device according to item 5.