JPH08122811A - Space light modulating element and its manufacture - Google Patents

Abstract

PURPOSE: To provide a space light modulating element which is few in cross talk between picture elements and the defect of the picture element, and can make reading under bright light and its manufacture. CONSTITUTION: A transparent conductive electrode 2 is formed on a glass substrate 1, and a photoconductive layer 6 consisting of amolphous silicon being pin diode composition is formed on the electrode 2 and moreover the layer 6 is filmed by aluminum, and isotropic etching is executed by reactive ion etching method using a picture element electrode 7 formed by photolithography as an etching mask, and the amolphous silicon between the picture element electrodes is removed, and polyimide is applied to the whole surface of the substrate for forming an insulated layer 10, and polymer containing carbon is further applied, and the whole surface of the substrate is etched by reactive ion etching, and the double layer structure of the insulated layer 10 and a light insulation layer 11 is formed between the picture elements.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a projection display,
The present invention relates to a spatial light modulator used in a holographic television or an optical arithmetic unit, and a manufacturing method thereof.

[0002]

2. Description of the Related Art A high-definition television having a large screen and high-density pixels has been actively developed. Among them, the projection display using liquid crystal technology is the conventional cathode ray tube (CR
Compared with the T) method, the luminance of the screen when using high-density pixels is less likely to decrease and the size can be easily reduced, and therefore, it is drawing attention. On the other hand, a projection display device using a transistor-driving liquid crystal panel is a promising method, but has problems such as a small aperture ratio, difficulty in manufacturing an element, and high cost. On the other hand, an optical writing type spatial light modulator using a CRT as an input means is attracting attention because it has advantages of a simple structure and a large aperture ratio.

Among such optical writing type spatial light modulators, one having the most basic structure can be given as shown in FIG. 7 (for example, C. Gomez et al. Japanese Journal Of).・ Applied Physics, Volume 30 (1991), pages L386 to L
388 pages (Jap. J. Appl. Phys. 30 (1
991) pp. L386-L388)). This is a transparent conductive electrode 7 formed on two substrates 701 and 712.
02 and 713, a photoconductive layer 706 and a liquid crystal layer 708 are sandwiched, and a plurality of metal pixel electrodes 7 are sandwiched therebetween.
07, alignment films 709 and 714, and a spacer 715 are arranged. However, in the case of this structure, the reading light 7
18 directly irradiates the photoconductive layer 706 between the adjacent pixel electrodes 707, which causes a problem that a malfunction occurs.

Further, as another structure having another basic structure, a dielectric reflection film is formed on the entire surface instead of the metal pixel electrode 707, and a light shielding layer is further formed on the entire surface (see, for example, JP-A-63-63). FIG. 7 of Japanese Patent No. 109422). However, in this case, there is a problem that the resolution deteriorates unless the electric resistance in the sheet direction of the dielectric reflection film or the light shielding layer is sufficiently increased.

The inventors of the present invention used an amorphous silicon layer having a pin photodiode structure as a light-receiving layer, and the structure of the light-receiving layer between pixels was such that the top n-layer was removed, or the bottom p-layer and top-layer were formed. Proposed a structure for reducing crosstalk between pixels by not providing the n-layer (Japanese Patent Application No. 3-344521, Japanese Patent Application No. 4-125846, Japanese Patent Application No. 4-136580, Japanese Patent Application No. 4-136580). 4-136581
issue).

Further, in order to further reduce the crosstalk between adjacent pixels and at the same time improve the degree of light shielding, a part or all of the photoconductive layer in the portion between pixels is removed, and a light shielding material having an insulating property therefor. Is used.
Such a structure is disclosed in, for example, Japanese Patent Laid-Open No. 2836/1989.

Further, a structure has been proposed in which the photoconductor is an island-like two-dimensional array surrounded by an insulator (for example, Japanese Patent Laid-Open No. 2-256026). In this case, crosstalk between pixels is reduced, but the light-shielding property is deteriorated. That is, the read light or the write light obliquely incident on the adjacent photoconductive layer through the insulator may cause a malfunction.

[0008]

As described above, a light-shielding material for forming a light-shielding layer between pixels has a sufficient light-shielding degree even if it is thin, and has an electric resistance sufficient to maintain resolution. Is required. Further, particularly in the case of the structure in which the groove portion is provided between the pixels as described above, when the light-shielding material with which the pixels are filled has a low resistance, it is provided between the pixels or between the pixel electrode and the transparent conductive electrode on the writing side. There is a problem that current leakage occurs, which causes crosstalk between pixels and pixel defects. Further, there is a manufacturing requirement that the space between the pixel electrodes should be easily filled.

However, in general, very few materials satisfy all of these requirements. For example, as a material that can be easily filled with a material having a high light-shielding degree that can block 99% or more of incident light with a thickness of about 1 μm, a polymer medium containing particles of a light-absorbing substance such as carbon can be used. Although conceivable, it is difficult to completely suppress crosstalk between pixels and pixel defects because the carbon particles themselves have electrical conductivity.

The inventors of the present invention, as shown in FIG. 8, form a groove by etching a part of the photoconductive layer 802 between the pixel electrodes 801, and form the light shielding layer 803 and the groove in the groove. It has been proposed to prevent current leakage between the pixel electrode and the transparent conductive electrode on the write side by disposing the insulating layer 804 (Japanese Patent Application No. 5-137400). However, in the case of such a configuration, the photoconductive layer remaining at the bottom between the pixels is irradiated with the writing light, which causes a malfunction. On the other hand, in order to improve the light blocking degree, it is necessary to partially remove the photoconductive layer below the eaves-shaped pixel electrode 801 in FIG. The photoconductive layer under the eaves is removed by isotropic etching by etching in the lateral direction at the same time as removing a part of the photoconductive layer between pixels. However, when a part of the photoconductive layer between the pixels remains, the amount of the photoconductive layer under the eaves that can be removed is limited, and a sufficient light blocking degree cannot be obtained.

In view of the above points, the present invention provides a spatial light modulator having a high degree of light shielding and a method of manufacturing the same, which has less crosstalk between pixels and pixel defects.

[0012]

In order to achieve the above object, a spatial light modulator according to the present invention comprises a first electrode and a second electrode arranged in parallel with the first electrode. ,
A divided photoconductive layer electrically contacting the first electrode, and a liquid crystal layer inserted between the second electrode and the photoconductive layer, the photoconductive layer on the liquid crystal layer side. A spatial light modulator having at least a pixel electrode in electrical contact with an interface, wherein a double layer of an insulating layer and a light-shielding layer is present in a groove-shaped gap portion between the photoconductive layers.

In the above structure, it is preferable that the groove-shaped gap portion between the photoconductive layers has a metal light-shielding film that substantially covers the bottom surface of the gap portion and is electrically separated from the pixel electrode.

Further, in the method of manufacturing a spatial light modulator according to the present invention, a photoconductive layer and pixel electrodes divided into minute shapes are formed on the first electrode, and the pixel electrode is used as an etching mask. The photoconductive layer by selective etching, an insulating layer is embedded in the gap between the divided pixel electrodes, a light shielding layer is further embedded on the insulating layer, and a part of the light shielding layer and the light shielding layer are formed by reactive ion etching. It is characterized in that a part of the insulating layer is removed.

It is preferable that the method includes a step of dividing the photoconductive layer and then forming a metal light-shielding film on the bottom portion of the gap between the divided pixel electrodes.

[0016]

According to the present invention, the degree of light shielding is ensured by embedding the light shielding layer on the first insulating layer embedded in the groove-shaped gap portion between the divided photoconductive layers. At this time, even when a material having a high light-shielding property but electrical conductivity, such as a polymer medium in which particles of a light-absorbing substance such as carbon are dispersed, is used as the light-shielding layer, the first insulating layer Due to
Electrical insulation is secured between the pixel electrodes, or between the pixel electrodes and the metal light-shielding film or the electrode at the bottom of the gap. This makes it possible to obtain a spatial light modulator having an improved light-shielding degree without losing its electrical insulation.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a sectional view showing an embodiment of a spatial light modulator according to the present invention. As shown in FIG. 1, a transparent conductive electrode 2 (for example, ITO (indium-tin oxide), SnO) is provided on a transparent substrate 1 (for example, glass).
₂ etc.) and the photoconductive layer 6 (eg,
Amorphous silicon semiconductor with diode structure:
p layer 3, i layer 4 and n layer 5), eaves-shaped pixel electrode 7
(For example, metal thin films of aluminum, chromium, titanium, etc.,
Alternatively, metal thin films obtained by stacking these are sequentially stacked. An alignment film 9 (for example, a polymer thin film such as polyimide) that aligns the liquid crystal 8 is formed thereon. Also,
An insulating layer 10 (for example, a polymer thin film such as polyimide) and a light shielding layer 11 for the reading light 21 are provided between these pixels.
(For example, a dye or a polymer containing carbon) is arranged. The transparent conductive electrode 13 and the alignment film 14 are also formed on the substrate 12 on the opposite side, these substrates are bonded together with a certain gap, and the liquid crystal 8 is injected into the gap. The thickness of the liquid crystal layer is controlled by the beads 15 dispersed as spacers.

The material used for the photoconductive layer 6 is, for example, Cd.
S, CdTe, CdSe, ZnS, ZnSe, GaA
Compound semiconductors such as s, GaN, GaP, GaAlAs and InP, amorphous semiconductors such as Se, SeTe and AsSe, Si, Ge, Si _1-x C _x , Si _1-x Ge _x , Ge _1-x
A polycrystalline or amorphous semiconductor such as C _x (0 <x <1), or (1) phthalocyanine pigment (abbreviated as Pc), for example, metal-free Pc, XPc (X = Cu, Ni, Co, Ti).
O, Mg, Si (OH) _2, etc.), AlClPcCl, T
iOClPcCl, InClPcCl, InClPc,
InBrPcBr and the like, (2) azo dyes such as monoazo dyes and disazo dyes, (3) penylene pigments such as penylene anhydride and penylene imide, (4) indigoid dyes, (5) quinacridone pigments, (6) anthraquinone , Polycyclic quinones such as pyrenequinones, (7) cyanine dyes, (8) xanthene dyes, (9) charge transfer complexes such as PVK / TNF, (10) eutectic crystals formed from pyrylium salt dyes and polycarbonate resins There are organic semiconductors such as complexes and (11) azurenium salt compounds.

Amorphous Si, Ge, Si _1-x C _x ,
_{Si 1-x Ge x, Ge} 1-x C x ( hereinafter, a-Si, a-G
e, a-Si _1-x C _x , a-Si _1-x Ge _x , a-Ge _1-x
When abbreviated as C _x ) is used as the photoconductive layer 6, hydrogen or a halogen element may be included, and oxygen or nitrogen may be included to reduce the dielectric constant or increase the resistivity. To control the resistivity, B and A which are p-type impurities
elements such as l and Ga, or P and A that are n-type impurities
Elements such as s and Sb may be added. In this way, the amorphous materials to which impurities are added are stacked to form pn, pi, in, p
It is also possible to form a junction such as in and form a depletion layer in the photoconductive layer 6 to control the dielectric constant and dark resistance or the operating voltage polarity. Not only such an amorphous material, but also two or more kinds of the above materials may be laminated to form a heterojunction to form a depletion layer in the photoconductive layer 6. In addition, the photoconductive layer 6
The film thickness is preferably in the range of 0.1 to 10 μm.

In this embodiment, amorphous silicon, which has the characteristic that the dark resistance is relatively high, is used. Further, a pin structure having a rectifying property is mainly used because erasing light is not required when actually driving.

As the alignment film 9, a polymer thin film of nylon, polyimide or the like or a SiO ₂ oblique vapor deposition film is useful. The thickness of the alignment film 9 is preferably 0.1 μm or less, and more preferably 0.01 μm or less.

The liquid crystal layer 8 is TN (twisted
A liquid crystal having a (nematic) structure may be used, but it is preferable to use a ferroelectric liquid crystal capable of obtaining a faster response. Alternatively, antiferroelectric liquid crystal may be used. The thickness of the liquid crystal layer is preferably 0.1 to 50 μm. Further, the light shielding layer 11 is preferably made of a material in which a polymer contains a dye or carbon.

Next, an embodiment of a method of manufacturing the spatial light modulator having the above structure will be described with reference to FIG.

First, 0.1 μm of ITO was sputtered on a glass substrate 1 of 55 mm × 45 mm × 1.1 mm.
The transparent conductive electrode 2 is formed by forming a film with a thickness of m. Next, amorphous silicon having a pin photodiode structure is deposited by the plasma CVD method to form the photoconductive layer 6. Here, the p-layer 3 contains 40% boron as an impurity.
0 ppm, and the n layer 5 is doped with 40 ppm of phosphorus. The p layer, the i layer, and the n layer each have a thickness of 0.1 μm.
m, 1.3 μm, and 0.5 μm. Next, aluminum is formed into a film having a thickness of 0.5 μm on the amorphous silicon film by a vacuum evaporation method, and the pixel electrode 7 is formed by dividing the film into minute shapes by photolithography. The size of the pixel electrode 7 is 20 μm × 20 μm, and the width between pixels is 5
and [mu] m, the number of pixels is set to 10 ⁶ (1000 × 1000) (or, FIG. 2 (a), (b) ).

Next, using the pixel electrode 7 as an etching mask, isotropic etching is performed using SF ₆ gas by the reactive ion etching method to remove the amorphous silicon between the pixel electrodes. At this time, a part of the lower portion of the pixel electrode 7 is also etched (FIG. 2C).

Next, use polyimide as a spinner on the entire surface of the substrate.
To a thickness of 0.2 μm to form the insulating layer 10.
(FIG. 2 (d)). Furthermore, from above, carbon-containing polymer
(Fuji Hunt, CK-2000) with a spinner
The light-shielding layer 11 is formed by applying a film having a thickness of 2 μm (see FIG. 2).
(E)). Then, by a reactive ion etching method, O
₂ Use gas to cover the entire surface of the pixel electrode 7 until it is exposed.
Etching. In this way, the insulating layer 10 is provided between the pixels.
Then, a two-layer structure of the light shielding layer 11 is formed. From the above,
1 has the photoconductive layer 6 of the spatial light modulator 16 shown in FIG.
One substrate is obtained.

Next, polyimide alignment films 9 and 14 are deposited on the substrate thus obtained and the counter substrate on which the transparent conductive electrode 13 made of ITO is formed on the glass substrate 12. The alignment treatment of the alignment film is performed by rubbing the surface in a certain direction with a nylon cloth. Next, beads 15 having a diameter of 1 μm dispersed in isopropyl alcohol were placed on the counter substrate.
Is sprayed. Then, the periphery of both substrates 1 and 12 is sealed with a UV curable resin to produce a liquid crystal cell. Ferroelectric liquid crystal 8 (C, manufactured by Chisso Corp.)
S-1029) is injected, and heat treatment is performed to make uniform orientation. As described above, the spatial light modulator 1 having the structure of FIG.
6 is obtained.

The spatial light modulator 1 thus obtained
6 is driven by applying a pulse voltage 17 between the transparent conductive electrodes 2 and 13. Input information is written in the photoconductive layer 6 by the writing light 18 from the transparent substrate 1 side. That is, the electric resistance of the photoconductive layer 6 decreases according to the intensity of the writing light 18, and the ferroelectric liquid crystal layer sandwiched between the pixel electrode 7 having a minute shape corresponding to each pixel and the transparent conductive electrode 13 facing it. The voltage applied to 8 increases,
The orientation of the ferroelectric liquid crystal layer 8 changes accordingly. Read-out light 21 of linearly polarized light that passes through the ferroelectric liquid crystal layer 8
Is reflected by each pixel electrode 7, passes through the ferroelectric liquid crystal layer 8 again, passes through the analyzer 20, and its light intensity change is read out as output light 22.

FIG. 3 shows the change over time in the intensity of the output light from the pixel when the applied drive voltage pulse and the writing light with a wavelength of 550 nm are used. The drive voltage pulse includes an erase pulse 301 (voltage Ve, width Te) and a write pulse 30.
2 (voltage Vw, width Tw). When the erasing pulse 301 is applied to the spatial light modulation element 16 in which the photoconductive layer 6 having a rectifying property and the ferroelectric liquid crystal layer 8 are connected in series, a forward voltage is applied to the photoconductive layer 6 to cause ferroelectricity. Liquid crystal 8 is forcibly turned off. Next, when the write pulse 302 is applied, the photoconductive layer 6 is in the reverse bias state, but the charge generated in the photoconductive layer 6 is carried to the pixel electrode 7 depending on the intensity of the write light 18, and as a result, The voltage applied to the ferroelectric liquid crystal layer 8 changes. With this change, the orientation of the ferroelectric liquid crystal layer 8 changes to the ON state. This liquid crystal alignment is
When the intensity of the writing light 18 increases and the amount of electric charge generated per unit time increases, the transient response thereof becomes faster.
Therefore, the reflected light intensity change averaged over time has a halftone.

In addition to the pulses shown in FIG. 3, for example,
C. Gomez and others Japanese Journal of Applied Physics Volume 30 (1991) L386
Pages L388 (Jap. J. Appl. Phy
s. 30 (1991) pp. It is of course also possible to drive with bipolar pulses as given in L386-L388).

The spatial light modulator manufactured as described above was evaluated as a projection display. FIG. 4 shows a schematic view of the projection display device.

As the information to be written in the spatial light modulator 16, the image of the CRT 401 is used, and the reading light 402 from the reading light source (metal halide lamp) is used as the condenser lens 403 and the polarization beam splitter 404.
The spatial light modulator 16 is irradiated with the light through the light source, and the output image is taken out through the analyzer 405 and the lens 406.
It was projected on 07. Although the effective area of the spatial light modulator 16 is 2.5 cm square, this is 1 on the screen 407.
Enlarged to 00 cm square. The drive pulse is the pulse shown in FIG. 3, Ve = 15V, Te = 100 μsec, Vw = −
The setting was 1.35 V and Tw = 1100 μsec.

The image displayed on the screen 407 by this projection display faithfully reproduced the input image of the CRT 401. The contrast ratio (output with writing light / output without writing light) on the screen 407 was 100: 1. On the other hand, there were few defective pixels that moved differently from normal pixels. Also, crosstalk between adjacent pixels was hardly observed.

The reason why such high quality display is possible is that a short circuit between the pixel electrode 7 and the transparent conductive electrode 2 is caused by forming a double layer of an insulating layer and a light shielding layer between the pixels. At the same time, to prevent the read light from being blocked,
This is because the pixels are electrically completely separated by the division of the photoconductive layer. However, as the output of the metal halide lamp of the light source was increased, the contrast ratio on the screen 407 decreased. This indicates that the light blocking degree is insufficient only with the insulating layer 10 and the light blocking layer 11 between the pixels. In addition, instead of CRT401, TFT
The same was true when writing was performed using a liquid crystal panel.

(Embodiment 2) FIG. 5 is a sectional view showing another embodiment of the spatial light modulator according to the present invention. The configuration of the spatial light modulator 50 shown in FIG. 5 is the same as that of the spatial light modulator 1 shown in FIG.
In addition to the structure of No. 6, a metal light-shielding film 51 (for example, a thin film of aluminum, chromium, titanium, etc.) is introduced at the bottom of the groove-shaped gap portion between the divided photoconductive layers 6. The metal light-shielding film 51 reflects a small amount of readout light 21 that has passed through the light-shielding layer 11 and the insulating layer 10 between pixels,
This leakage light is prevented from being reflected on the back surface of the transparent substrate 1 and reaching the photoconductive layer 6, thereby further improving the light shielding degree.
Thereby, the brightness can be further improved in the projection system.

An embodiment of the method of manufacturing the spatial light modulator 50 will be described with reference to FIG. First, Example 1
Forming a transparent conductive electrode 2 on the glass substrate 1 in the same manner as
Further, amorphous silicon having a pin photodiode structure is deposited by the plasma CVD method, and the photoconductive layer 6 is formed.
To form. Next, similarly to the first embodiment, the pixel electrode 7 is formed on the amorphous silicon. However, chromium was used as the electrode material instead of the aluminum used in Example 1, and the film thickness was set to 0.5 μm (FIG. 6A).
(B)).

Next, as in the first embodiment, the pixel electrode 7
Is used as an etching mask to remove the amorphous silicon between the pixel electrodes by reactive ion etching (FIG. 6C). Next, aluminum is applied to the entire surface of the substrate in an amount of 0.
A film with a thickness of 05 μm is formed, and a metal light-shielding film 5 is formed on the bottom between pixels.
1 and the metal reflection film 52 is formed on the pixel electrode 7 (FIG. 6D). Then, in the same manner as in Example 1,
An insulating layer 10 and a light shielding layer 11 are formed (FIG. 6 (e),
(F), (g)), alignment treatment, substrate bonding, and ferroelectric liquid crystal 8 injection are performed to obtain the spatial light modulator 50.

The spatial light modulator 50 manufactured as described above was evaluated as the projection type display shown in FIG. 4 as in the case of Example 1. With this projection display, the image projected on the screen 407 is displayed on the CRT.
The input image of 401 was faithfully reproduced. Screen 4
The contrast ratio on 07 was 100: 1. On the other hand, almost no defective pixels that moved differently from normal pixels were seen, and crosstalk between adjacent pixels was hardly observed. In addition, the illuminance of the reading light is 2 million l
Even when x or more, the contrast ratio is maintained at 100: 1, and at this time, the entire white state is 1 on the screen 407.
A brightness of 000 lm or more was obtained. This indicates that the light shielding degree was further improved by the introduction of the metal light shielding film 51.

[0040]

As described above, according to the spatial light modulator of the present invention, most of the read light emitted from the liquid crystal layer side, which is emitted between pixels, is shielded between pixels. By being absorbed by the layers, it is possible to realize a spatial light modulator having a high light blocking ability. In addition, by dividing the photoconductive layer and further providing an insulating layer below the light shielding layer, it is possible to prevent short circuits between pixels and between the pixel electrodes and the transparent conductive electrodes below the photoconductive layer. As a result, a high contrast display with almost no crosstalk in the projection system and almost no defective pixels is possible.

Further, in the above-mentioned structure, a preferable structure is such that the groove-like gap portion between the photoconductive layers has a metal light-shielding film which substantially covers the bottom surface of the gap portion and is electrically separated from the pixel electrode. For example, since it is possible to reflect a small amount of read light that has passed through the light-shielding layer and the insulating layer,
Further, the degree of light shielding can be improved. As a result, it is possible to improve the brightness in the projection system.

Further, according to the method of manufacturing a spatial light modulator according to the present invention, the spatial light modulator having the above structure can be efficiently and reasonably manufactured.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a spatial light modulator according to the present invention.

2A to 2F are process drawings showing an embodiment of a method for manufacturing a spatial light modulator according to the present invention.

FIG. 3 is a diagram showing a change with time of a driving voltage pulse and an intensity of output light from a pixel according to the present embodiment.

FIG. 4 is a schematic diagram of a projection display system manufactured using the spatial light modulator of this embodiment.

FIG. 5 is a cross-sectional view showing another embodiment of the spatial light modulator according to the present invention.

6A to 6G are process diagrams showing another embodiment of the method for manufacturing a spatial light modulator according to the present invention.

FIG. 7 is a sectional view of a conventional spatial light modulator.

FIG. 8 is a sectional view of another conventional spatial light modulator.

[Explanation of symbols]

 1, 12 Transparent substrate 2, 13 Transparent conductive electrode 6 Photoconductive layer 7 Pixel electrode 8 Ferroelectric liquid crystal 9, 14 Alignment film 10 Insulating layer 11 Light-shielding layer 15 Beads 16 Spatial light modulator 17 Pulse voltage 18 Writing light 19 Polarization Child 20 Analyzer 21 Readout light 22 Output light

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Junko Asayama 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Kazuhiro Nishiyama, 1006, Kadoma, Kadoma City, Osaka

Claims (4)

[Claims] 1. A first electrode, a second electrode arranged parallel to the first electrode, a divided photoconductive layer in electrical contact with the first electrode, and the first electrode. A second electrode and a liquid crystal layer inserted between the photoconductive layer, and at least a pixel electrode in electrical contact with an interface of the photoconductive layer on the liquid crystal layer side, and a groove between the photoconductive layers. A spatial light modulation element characterized in that a double layer of an insulating layer and a light-shielding layer is present in the gap portion of the shape. 2. A spatial light modulator according to claim 1, further comprising a metal light-shielding film, which substantially covers the bottom surface of the gap and is electrically separated from the pixel electrode, in the groove-like gap between the photoconductive layers. 3. A photoconductive layer and a pixel electrode divided into minute shapes are formed on the first electrode, and the photoconductive layer is divided by isotropic etching using the pixel electrode as an etching mask. Manufacturing a spatial light modulator in which an insulating layer is embedded in a gap between pixel electrodes, a light shielding layer is embedded on the insulating layer, and a part of the light shielding layer and a part of the insulating layer are removed by reactive ion etching. Method. 4. The method for manufacturing a spatial light modulator according to claim 3, further comprising the step of forming a metal light-shielding film on the bottom portion of the gap between the divided pixel electrodes after dividing the photoconductive layer.