JPH10268359A - Semiconductor device and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reflection type LCD which has high-definition display performance. SOLUTION: On a metal thin film 104, a resist mask 105 is arranged selectively and an exposed part 106 is formed. In this state, only the exposed part 106 is oxidized through an anode oxidizing process and anode oxide 107 is produced. Then the metal thin film 104 is completely and insulated soon by the anode oxide 107 to form pixel electrodes 108 and 109. At this time, the gap between the pixels is filled with the anode oxide 107 and a reflection type LCD can be obtained which has a very flat reflecting surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a configuration of a reflection type liquid crystal display device. In particular, the present invention relates to a configuration of an active matrix reflective display device including a semiconductor device using a semiconductor thin film. Further, the present invention can be applied to an electro-optical device having such a reflective display device.

[0002] In this specification, "semiconductor device"
Refers to all devices that function by utilizing semiconductors. Therefore, the reflective display device and the electro-optical device are also included in the category of the semiconductor device. However, in the specification, words such as a reflective LCD and an electro-optical device are used properly for easy distinction.

[0003]

2. Description of the Related Art In recent years, development of projectors and the like using a reflection type liquid crystal display device (hereinafter referred to as a reflection type LCD) as a projection display has been actively promoted. Reflective type L
Since a CD has less light loss than a transmissive LCD, it is advantageous in efficiently using the light of the backlight and displaying a high-definition image.

[0004] Further, with the rapid spread of portable information terminal devices (portable devices) such as mobile computers and mobile phones (including PHS), demands for direct-view display displays are increasing. Since a reflective LCD can display an image without using a backlight, the size, weight, and power consumption of a portable device can be reduced.

Here, a brief description will be given of a process of manufacturing a pixel matrix circuit of a conventional reflection type LCD. Note that a pixel matrix circuit is a circuit in which thin film transistors (TFTs) for controlling an electric field applied to liquid crystal are arranged in a matrix, and constitutes an image display area of a liquid crystal display device.

First, in FIG. 2, 201 is a substrate having an insulating surface, 202 is an active layer of a first pixel TFT, 203
Is an active layer of the second pixel TFT. First pixel TFT
The distance between the pixel TFT and the second pixel TFT corresponds to the pixel pitch, and tends to be shorter as the display becomes higher in definition.

Reference numeral 204 denotes a gate insulating film. Then, gate electrodes 205 and 206 are formed thereon. The gate electrodes 205 and 206 are connected to a gate line (not shown). Thus, the state shown in FIG. 2A is obtained.

Next, impurity ions imparting one conductivity (phosphorus (P) for N-type and boron (B) for P-type) are added to the active layers 202 and 203. As a result, source regions 207 and 208, drain regions 209 and 210, and channel formation regions 211 and 212 are formed. (Figure 2
(B))

Next, a first interlayer insulating film 213 is formed,
A contact hole is opened to form source electrodes 214 and 215 and drain electrodes 216 and 217. Thus, the state shown in FIG. 2C is obtained.

Further, a second interlayer insulating film 218 is formed, and a black mask 219 is formed thereon. A third interlayer insulating film 220 is formed thereon, and finally a pixel electrode 221 is formed. The pixel electrode 221 is formed of a metal thin film that reflects incident light, and has a function as a reflection electrode.
(FIG. 2 (D))

[0011] At this time, the black mask 219 is disposed below a region that becomes a gap between the pixel electrodes (reflection electrodes) 221. In FIG. 2 (D), although they look like individual patterns, they are actually all connected in a matrix. The black mask 219 arranged in this way plays a role of cutting light leaked from the gap between the pixel electrodes 221.

Through the above steps, a pixel matrix circuit as shown in FIG. 2D is completed. After that, the liquid crystal is sandwiched between the substrate on which the pixel matrix circuit is formed by the known cell assembling process and the opposing substrate, thereby forming the reflection type L.
The CD is completed.

[0013]

In the pixel matrix circuit having the conventional structure shown in FIG. 2D, boundaries 223 and 224 of the electrodes (hereinafter simply referred to as boundaries) always exist between the pixel electrodes. That is, a step corresponding to the film thickness of the pixel electrode is formed.

[0014] Such a step causes poor alignment of the liquid crystal material, which causes disturbance of the displayed image. In addition, irregular reflection of incident light generated at the step portion causes a reduction in contrast and a reduction in light use efficiency.

As described above, in the conventional structure, there is a problem that the boundary portion (accurately, a step) formed between the pixel electrodes deteriorates the display performance of the reflective LCD. In particular, projection displays used for projectors
Since the size of the display is extremely small, the above-mentioned problem becomes obvious.

The present invention solves the above problems and discloses means for forming a very high-definition reflective LCD.

[0017]

According to the structure of the invention disclosed in this specification, a plurality of electrodes are formed on a substrate having an insulating surface, and the plurality of electrodes mainly include a material constituting the electrodes. It is characterized by being insulated and separated from each other by an oxide as a component.

In another aspect of the present invention, a first substrate and a second substrate having a light-transmitting property, a liquid crystal layer sandwiched between the first substrate and the second substrate, At least, the first substrate and the second substrate are formed with striped electrodes, and the striped electrodes formed on the first substrate are made of a material forming the electrodes. It is characterized by being insulated and separated from each other by an oxide as a main component.

According to another aspect of the invention, at least a plurality of semiconductor elements formed in a matrix on a substrate having an insulating surface and a plurality of pixel electrodes connected to each of the plurality of semiconductor elements are provided. Wherein the plurality of pixel electrodes are insulated and separated from each other by an oxide containing a material constituting the pixel electrodes as a main component.

Further, according to another aspect of the invention, a substrate having a plurality of semiconductor elements formed in a matrix and a plurality of pixel electrodes connected to each of the plurality of semiconductor elements, and being held on the substrate And a liquid crystal layer, wherein the plurality of pixel electrodes are insulated and separated from each other by an oxide containing a material constituting the pixel electrodes as a main component.

In the above configuration, a typical example of a state where the liquid crystal layer is held is a substrate having a plurality of pixel electrodes (first substrate) and a counter substrate facing the first substrate (second substrate). Refers to a state in which a liquid crystal layer is sandwiched therebetween. When PDLC (polymer dispersed liquid crystal) is used as the liquid crystal layer, the liquid crystal layer itself may be solidified, so that the second substrate may not be required in some cases.

A typical example of the semiconductor element is a thin film transistor (TFT). In addition, an insulating gate type field effect transistor (IGFET), a thin film diode, an MIM (Metal-Insulator-Metal) element, a varistor element and the like can be used. good.

In another aspect of the invention, a metal thin film is formed on a substrate having an insulating surface, a resist mask is selectively formed on the metal thin film, and the resist mask is used as a mask. Oxidizing the exposed portion of the metal thin film and transforming the exposed portion into an oxide, wherein the metal thin film is insulated and separated into a plurality by the oxide.

In another aspect of the invention, a first substrate and a second substrate having a light transmitting property, a liquid crystal layer sandwiched between the first substrate and the second substrate, Forming a metal thin film on the first substrate, selectively forming a resist mask on the metal thin film, and using the resist mask as a mask. Oxidizing the exposed portion of the metal thin film and transforming the exposed portion into an oxide,
The metal thin film is insulated and separated in a stripe shape by the oxide.

According to another aspect of the invention, there is provided a semiconductor device comprising: a step of forming a plurality of semiconductor elements on a substrate having an insulating surface; a step of forming a metal thin film electrically connected to the plurality of semiconductor elements; Selectively forming a resist mask on the thin film, oxidizing an exposed portion of the metal thin film using the resist mask as a mask, and transforming the exposed portion to an oxide, at least comprising: The metal thin film is insulated and separated in a matrix.

According to another aspect of the present invention, there is provided a substrate having a plurality of semiconductor elements formed in a matrix and a plurality of pixel electrodes connected to each of the plurality of semiconductor elements, and a substrate held on the substrate. A method for manufacturing a semiconductor device including at least a liquid crystal layer, wherein a step of forming a metal thin film electrically connected to the plurality of semiconductor elements, and a step of selectively forming a resist mask on the metal thin film Oxidizing the exposed portion of the metal thin film using the resist mask as a mask, and transforming the exposed portion into an oxide, wherein the metal thin film is insulated and separated in a matrix by the oxide. And

The step of oxidizing the exposed portion of the metal thin film is preferably performed by an anodic oxidation method. For that purpose, it is necessary to use an anodizable material (such as aluminum or tantalum) as the metal thin film. In particular, aluminum or a material containing aluminum as a main component has an advantage that a high reflectance can be obtained.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A brief description of the present invention will be given with reference to FIG. In FIG. 1A, 10
1 is a substrate having an insulating surface, 102 is a first pixel TFT formed on the substrate 101, 103 is a second pixel TFT
It is.

Further, the first pixel TFT 102 and the second
A metal thin film 104 connected to the pixel TFT 103 is formed. The metal thin film 104 is formed of aluminum or a material containing aluminum as a main component.

The resist mask 10 is formed on the metal thin film 104.
5 is arranged at a position to be a pixel electrode later. Then, the substrate 101 is immersed in the electrolytic solution in this state,
04 is anodized. In this case, only the exposed portion (opening of the resist mask) 106 of the metal thin film is in contact with the electrolytic solution, so that only this region can be selectively anodized.

As shown in the enlarged view of the anodized portion, the exposed portion 1
In 06, anodic oxidation proceeds from the surface of the metal thin film 104,
An insulating anodic oxide 107 is formed. When an oxalic acid aqueous solution is used as the electrolytic solution, the anodic oxide 107 becomes porous.

Therefore, the electrolytic solution also penetrates into the anodic oxide 107, and the film thickness increases in the direction indicated by the arrow in accordance with the anodic oxidation time. Then, the anodic oxide 107 finally reaches the underlying interlayer insulating film, and the growth of the anodic oxide 107 stops.

When the anodic oxide 107 stops, the anodic oxidation is stopped, and the resist mask 105 is removed to obtain the state shown in FIG. In this state, the metal thin film 104 is completely insulated and separated by the anodic oxide 107, and the pixel TF
A pixel electrode 108 of T102 and a pixel electrode 109 of the pixel TFT 103 are formed.

Actually, 100 is provided for the pixel matrix circuit.
Ten thousand or more pixel TFTs are formed in a matrix, and the same number of pixel electrodes are formed thereon in a matrix. Thus, the present invention patterns the metal thin film 104,
It is characterized in that pixel electrodes that are insulated and separated from each other are formed by anodic oxidation instead of etching.

Therefore, the gap between the pixel electrodes is filled with the anodic oxide, so that an unnecessary step is not formed. Therefore, there are no problems such as the conventional defective orientation of the liquid crystal material and irregular reflection of light at the step.

[0036]

【Example】

[Embodiment 1] In this embodiment, a reflection type LC using the present invention is used.
An example of a process for manufacturing the D pixel matrix circuit will be described with reference to FIGS. Note that, since the present invention is a technique relating to flattening of a pixel, the TFT structure itself is not limited to this embodiment.

First, a substrate 301 having an insulating surface is prepared. In this embodiment, a silicon oxide film is formed as a base film on a glass substrate. Active layers 302 to 304 made of a crystalline silicon film are formed on a substrate 301. In this embodiment, only three TFTs are described.
More than 100,000 TFTs are formed in the pixel matrix circuit.

In this embodiment, a crystalline silicon film is obtained by thermally crystallizing an amorphous silicon film. Then, the crystalline silicon film is patterned by a normal photolithography process to form an active layer 30.
Obtain 2-304. In this embodiment, a catalyst element (nickel) for promoting crystallization is added during crystallization.
This technique is described in detail in JP-A-7-130652.

Next, a silicon oxide film having a thickness of 150 nm is formed as a gate insulating film 305, and an aluminum film (not shown) containing 0.2% by weight of scandium is formed thereon, followed by patterning. An island-like pattern serving as a prototype of the gate electrode is formed.

In this embodiment, the technique described in Japanese Patent Application Laid-Open No. Hei 7-135318 is used. For details, refer to the publication.

First, anodization is performed in a 3% oxalic acid aqueous solution while leaving the resist mask used for patterning on the island pattern. At this time, a formation current of 2 to 3 mV is passed using the platinum electrode as a cathode, and the ultimate voltage is 8 V. Thus, the porous anodic oxide films 306 to 308
Is formed.

Then, after removing the resist mask, 3
Anodizing is performed in a solution obtained by neutralizing a solution of tartaric acid in ethylene glycol with aqueous ammonia. At this time, the formation current may be 5 to 6 mV, and the ultimate voltage may be 100 V. Thus, dense anodic oxide films 309 to 311 are formed.

Then, the gate electrode 31 is formed by the above steps.
2-314 are defined. In the pixel matrix circuit, a gate line connecting each gate electrode is formed for each line at the same time when the gate electrode is formed. (FIG. 3 (A))

Next, the gate insulating film 305 is etched using the gate electrodes 312 to 314 as a mask. The etching is performed by a dry etching method using CF ₄ gas. As a result, a gate insulating film having a shape as indicated by reference numerals 315 to 317 is formed.

Then, in this state, impurity ions imparting one conductivity are added by an ion implantation method or a plasma doping method. In this case, if the pixel matrix circuit is composed of N-type TFTs, P (phosphorus) ions are converted to P-type TFs.
If it is composed of T, B (boron) ions may be added.

The step of adding the impurity ions is performed twice. The first time is performed at a high accelerating voltage of about 80 keV, and the adjustment is performed so that the peak of the impurity ion comes below the ends (projections) of the gate insulating films 315 to 317. The second time is performed at a low accelerating voltage of about 5 keV, so that impurity ions are not added below the ends (projections) of the gate insulating films 315 to 317.

Thus, the source regions 318 to 32 of the TFT
0, drain regions 321 to 323, low-concentration impurity regions (also called LDD regions) 324 to 326, and channel formation regions 327 to 329 are formed. (FIG. 3 (B))

At this time, the source / drain region is 300 to 50
It is preferable to add impurity ions to such an extent that a sheet resistance of 0 Ω / □ is obtained. The low-concentration impurity region is T
It is necessary to perform optimization according to the performance of the FT. Also,
After the impurity ion addition step is completed, heat treatment is performed to activate the impurity ions.

Next, a silicon oxide film is formed as a first interlayer insulating film 330 to a thickness of 400 nm, and a source electrode 3
31 to 333 and drain electrodes 334 to 336 are formed. (FIG. 3 (C))

Next, an organic resin film is formed as a second interlayer insulating film 337 to a thickness of 1 to 2 μm. As the organic resin film, polyimide, polyamide, polyimide amide, acrylic, or the like can be used.

Then, a metal thin film 33 to be a pixel electrode later
8 is formed to a thickness of 100 nm. In this embodiment, an aluminum film to which 1% by weight of titanium is added is used as the metal thin film, but tantalum or the like, which is an anodizable material, can be used in the present invention.

Next, after forming the metal thin film 338, a resist mask 339 is formed. At this time, the structure is such that the resist mask 339 is arranged only in a region to be functioned as a pixel electrode later. That is, in the state shown in FIG. 3D, the resist masks 339 are arranged in a matrix, and the exposed portion of the metal thin film 338 is only the region indicated by 340.

Here, FIG. 5A shows a view of the state shown in FIG. 3D as viewed from above. The structure shown in FIG.
(A) corresponds to a cross-sectional view taken along AA ′. Each symbol in FIG. 5A corresponds to the symbol used in FIG. That is, a resist mask 339 is formed in a matrix on the metal thin film 338.

When the state shown in FIG. 3D is obtained, anodic oxidation is performed in the electrolytic solution as it is. This anodic oxidation may be performed under the conditions for forming the porous anodic oxide film or the conditions for forming a dense anodic oxide film.

When the thickness of the metal thin film 338 exceeds 100 nm, it is preferable to perform the formation under the conditions for forming a porous anodic oxide film. Since the porous anodic oxide film is proportional to the anodic oxidation time and the film thickness, it can correspond to a thickness of about 2 μm. Therefore,
Even if the metal thin film 338 is thick, complete insulation can be achieved.

On the other hand, when the thickness of the metal thin film 338 is 100 nm or less, it is preferable to perform the formation under a condition for forming a dense anodic oxide film. A dense anodic oxide film is effective in that it has high insulation properties and high stability. However, since the thickness of the dense anodic oxide film is determined by the applied voltage during anodic oxidation, the upper limit is determined by the withstand voltage of the insulating film used as a mask for anodic oxidation.

In the above anodic oxidation step, only the exposed portion 340 of the metal thin film 338 is selectively anodized. Since the thickness of the porous anodic oxide film increases in proportion to time, finally, the metal thin film at the exposed portion is completely anodized (alumina represented by Al _x O _y in this embodiment) 341. Metamorphosis. Therefore, the metal thin film 338 is insulated and separated by the anodic oxide 341 and becomes the pixel electrodes 342 to 344. Then, by removing the resist mask 339, FIG.
Is obtained.

FIG. 5B shows this state as viewed from above. The structure in FIG. 4A is BB ′ in FIG. 5B.
It corresponds to the cross-sectional view cut by. Each symbol in FIG. 5B corresponds to the symbol used in FIG.

As a feature of the present invention, the pixel electrodes 342 to 3
The anodic oxide 341 is formed so as to fill the gap between the 44. Therefore, it is possible to bury the boundary between the pixel electrodes without requiring a complicated process. Also,
Since the pixel electrode surface almost matches the anodic oxide surface,
An excellent flat surface can be obtained.

As described above, the pixel matrix circuit is completed. Actually, a driving circuit for driving the pixel TFTs and the like are simultaneously formed on the same substrate. Such substrates are usually TFT
It is called a side substrate or an active matrix substrate. In this specification, the active matrix substrate is referred to as a first substrate.

When the first substrate is completed, the light transmitting substrate 34
A counter substrate (hereinafter, this substrate is referred to as a second substrate) on which a counter electrode 346 is formed is attached to the substrate 5 and a liquid crystal layer 347 is sandwiched between them. Thus, a reflective LCD as shown in FIG. 4B is completed.

The cell assembling step may be performed according to a known method. Further, a dichroic dye can be dispersed in the liquid crystal layer, or a color filter can be provided on the opposite substrate. The type of such a liquid crystal layer, the presence or absence of a color filter, and the like vary depending on the mode in which the liquid crystal is driven.

[Embodiment 2] In this embodiment, a semiconductor device for performing active matrix driving is described in Embodiment 1.
An example in which a TFT having a different structure from the TFT shown in FIG.

In Example 1, a typical top gate type TF
The coplanar type TFT which is T is described as an example,
It may be a bottom gate type TFT. FIG. 6 shows an inverted stagger type T which is a typical example of a bottom gate type TFT.
This is an example using FT.

In FIG. 6, reference numeral 601 denotes a glass substrate;
2, 603 is a gate electrode, 604 is a gate insulating film, 60
5, 606 are active layers. The active layers 605 and 606 are formed of a silicon film to which an impurity is not intentionally added.

Reference numerals 607 and 608 denote source electrodes, 60
Reference numerals 9 and 610 denote drain electrodes, and reference numerals 611 and 612 denote silicon nitride films serving as channel stoppers (or etching stoppers). That is, a region of the active layers 605 and 606 located below the channel stoppers 611 and 612 substantially functions as a channel formation region.

The above is the basic structure of the inverted staggered TFT. In this embodiment, such an inverted staggered structure is covered with an interlayer insulating film 613 made of an organic resin film and flattened, and pixel electrodes 614 and 615 are formed thereon. Of course,
The pixel electrodes 614 and 615 are insulated and separated by anodic oxides 616 and 617 using the present invention.

When fabricating a reflection type LCD, it is effective to adopt a structure as shown in FIG. 6 using an inverted stagger type TFT.
In such a structure, the pixel electrode can be formed above the inverted staggered TFT, so that the size of the pixel region can be maximized.

Next, an example in which an insulated gate field effect transistor (IGFET) is formed as a semiconductor device of the present invention will be described. IGFET is MO
Also called SFET, it refers to a transistor formed on a silicon wafer.

In FIG. 7, reference numeral 701 denotes a glass substrate;
Reference numerals 2 and 703 are source regions, and 704 and 705 are drain regions. The source / drain regions can be formed by adding impurities by ion implantation and thermally diffusing them. Note that 70
Reference numeral 6 denotes an oxide for element isolation, which can be formed using a normal LOCOS technique.

Next, 707 is a gate insulating film, 708 and 7
09 is a gate electrode; 710 is a first interlayer insulating film;
1, 712 is a source electrode, and 713, 714 are drain electrodes. The surface is flattened with a second interlayer insulating film 715, and pixel electrodes 716 and 717 are formed on the flat surface. Needless to say, the pixel electrodes 716 and 717 are made of a metal thin film (not shown) serving as a material of the pixel electrodes by anodizing 718 and 719.
Obtained by insulating and isolating.

The present invention can be applied to an active matrix display using a thin film diode, an MIM element, a varistor element, etc., in addition to the IGFET, the top gate type or the bottom gate type TFT shown in this embodiment.

As described above, as shown in the present embodiment, the present invention can be applied to a reflection type LCD using a semiconductor device having any structure.

In particular, the reflection type LCD has an advantage that the pixel area can be maximized by flattening the semiconductor element and forming the pixel electrode thereon. The present invention is an effective technique for utilizing the advantages more effectively. Therefore, the reflection type LCD using the present invention can realize high resolution and high aperture ratio.

Third Embodiment In the first embodiment, it is effective to planarize the second interlayer insulating film 337 before forming the metal thin film 338 to be a pixel electrode.

Examples of the method of flattening the interlayer insulating film include a method of increasing the thickness of the interlayer insulating film, a method of leveling using an organic resin film, a method of mechanical polishing, and a method of an etch-back technique. However, a mechanical polishing method is most effective for obtaining an excellent flat surface.

As a method by mechanical polishing, a CMP (Chemical Mechanical Polishing) technique is typically given. The CMP technique is a polishing technique that combines chemical etching with a chemical solution and mechanical polishing with an abrasive.

According to this embodiment, the pixel electrodes 342 to 344 are formed on an excellent flat surface, and a pixel electrode having a high reflectance can be obtained. That is, it is very effective when used for applications such as a projection display.

[Embodiment 4] The present invention can be applied to a simple matrix type reflection type LCD. In this case, stripe-shaped electrodes are formed on each of the pair of substrates, and the substrates are attached to each other so that the electrodes are orthogonal to each other to sandwich the liquid crystal layer.

In this case, if one is a light-transmitting substrate, the other may be light-transmitting or light-shielding. However, the stripe-shaped electrodes formed on the light-transmitting substrate side need to be formed of a transparent conductive film.

In this embodiment, a metal thin film made of aluminum or a material containing aluminum as a main component is formed on the substrate side paired with the light-transmitting substrate, and a resist mask is provided in the form of a stripe and anodized to form a stripe. Electrode is obtained.

[Embodiment 5] In a reflection type LCD formed by applying the present invention, various display modes of liquid crystal can be used. For example, ECB (Electric Field Controlled Birefringence) mode, PCGH (Phase Transition Type Guest-Host) mode, OC
B mode, HAN mode, and PDLC type guest / host mode are given.

The ECB mode is a display mode in which the voltage applied to the liquid crystal layer is changed to change the orientation of the liquid crystal, and the resulting change in the birefringence of the liquid crystal layer is detected by a pair of polarizing plates to perform color display. In this case, since a method that does not use a color filter can be adopted, a bright display can be achieved.

The PCGH mode is a display mode in which a dichroic dye is mixed with host molecules in a host liquid crystal, the orientation of the liquid crystal molecules is changed by a voltage applied to the liquid crystal, and the light absorption of the liquid crystal layer is changed. It is. In this case, since a method without using a polarizing plate can be adopted, high contrast can be obtained.

The PDLC mode is a display mode using a polymer dispersed liquid crystal in which a polymer is dispersed in a liquid crystal (or a liquid crystal is dispersed in a polymer). in this case,
Since a polarizing plate is not required, bright display is possible. Further, if a solid polymer-dispersed liquid crystal is used, a configuration without using a glass substrate on the opposite side is also possible.

In these various display modes, the presence / absence of a polarizing plate and the presence / absence of a color filter can be freely set according to the characteristics. For example, in the case of the PCGH mode, a polarizing plate is unnecessary, so that a bright display can be realized even with a single-plate type using a color filter.

[Embodiment 6] In this embodiment, an example in which the reflection type LCD of the present invention is applied to a three-panel projector will be described. The description will be made using the schematic diagram shown in FIG.

In FIG. 8, R (red) output from a light source 801 such as a metal halide lamp or a halogen lamp,
Light including B (blue) and G (green) is reflected by the polarization beam splitter 802 and cross-dichroic mirror 803.
Proceed to.

Note that the polarizing beam splitter is an optical filter having a function of reflecting or transmitting light depending on the polarization direction of light. In this case, the light from the light source 801 is given a polarized light that is reflected by the polarizing beam splitter 802.

At this time, the cross dichroic mirror 80
In No. 3, the R component light is reflected in the direction of the liquid crystal panel 804 corresponding to R, and the B component light is reflected in the direction of the liquid crystal panel 805 corresponding to B. The G component light passes through the cross dichroic mirror 803 and enters the liquid crystal panel 806 corresponding to G.

In each of the liquid crystal panels 804 to 806, the liquid crystal molecules are oriented so that the incident light is reflected without changing the polarization direction when the pixel is off. When the pixel is in the ON state, the orientation state of the liquid crystal layer changes, and the polarization direction of the incident light changes accordingly.

The light reflected by the liquid crystal panels 804 to 806 is reflected again by the cross dichroic mirror 803 (only the G component light is transmitted) and combined, and then enters the polarization beam splitter 802 again.

At this time, the light reflected by the pixel region in the ON state changes its polarization direction and passes through the polarization beam splitter 802. On the other hand, the light reflected by the pixel region in the off state is reflected by the polarization beam splitter 803 because the polarization direction does not change.

As described above, the pixel regions arranged in a matrix in the pixel matrix circuit are turned on / off by a plurality of semiconductor elements.
By performing the off control, only the light reflected by the specific pixel region can pass through the polarizing beam splitter 802. This operation is common to the liquid crystal panels 804 to 806.

As described above, the polarization beam splitter 80
The light including image information transmitted through the projection screen 2 is enlarged and projected by an optical lens 807 including a projection lens or the like, and
08.

The reflection type LCD utilizing the present invention realizes high resolution and high aperture ratio by embedding between pixel electrodes. Therefore, excellent display performance can be realized even in an electro-optical device that enlarges and projects an image like the projection type projector in FIG.

[Embodiment 7] In this embodiment, an applied product (electro-optical device) to which the reflection type LCD according to the present invention can be applied will be described with reference to FIG. Examples of the electro-optical device using the present invention include a video camera, a still camera, a projector, a head-mounted display, a car navigation, a personal computer, a portable information terminal (a mobile computer, a mobile phone, and the like).

FIG. 9A shows a mobile computer (mobile computer), which includes a main body 2001 and a camera unit 2.
002, an image receiving unit 2003, operation switches 2004, and a display device 2005. Display device 2005
, Further reduction in size and power consumption can be achieved.

FIG. 9B shows a head-mounted display, which includes a main body 2101, a display device 2102, and a band 2
103. By applying the present invention to the display device 2102, the size of the device can be significantly reduced.

FIG. 9C shows a front type projector, which includes a main body 2201, a light source 2202, and a display device 220.
3. It is composed of an optical system 2204 and a screen 2205. By applying the present invention to the display device 2203, a high-definition image is realized.

FIG. 9D shows a mobile phone, and the main body 230 is shown.
1, audio output unit 2302, audio input unit 2303, display device 2304, operation switch 2305, antenna 2306
It consists of. By applying the present invention to the display device 2304, a display monitor with excellent visibility can be mounted.

FIG. 9E shows a video camera,
401, display device 2402, audio input unit 2403, operation switch 2404, battery 2405, image receiving unit 240
6. By applying the present invention to the display device 2402, display performance that can sufficiently withstand shooting outdoors can be realized.

FIG. 9F shows a rear type projector, which includes a main body 2501, a light source 2502, a display device 2503,
Polarizing beam splitter 2504, reflector 250
5, 2506 and a screen 2507. By applying the present invention to the display device 2402, the device can be made thinner and a high-definition image can be realized.

Note that FIGS. 9 (A), (B), (D),
In the case of a direct-view display as shown in (E), it is effective to form irregularities on the surface of the pixel electrode. This enhances the light scattering effect and improves the viewing angle and visibility.
Conversely, in the case of a projection type display as shown in FIGS. 9C and 9F, it is preferable that the surface of the pixel electrode be in a mirror state. Thereby, irregular reflection of light is reduced, and color shift and a decrease in resolution are suppressed.

As described above, the applicable range of the present invention is extremely wide, and it can be applied to display media in all fields. In particular, when an LCD is used for a projection display device such as a projector, a very high resolution is required.
In such a case, the present invention is a very effective technique.

Also, mobile computers, mobile phones,
2. Description of the Related Art For portable information terminal devices represented by video cameras, it is desired to reduce the size and power consumption of the devices. In such a case, the reflective LCD of the present invention which does not require a backlight is effective.

[0107]

The reflection type LCD using the present invention has a configuration in which the gaps (intervals between pixels) between the individual pixel electrodes arranged in a matrix are filled with an insulator. At this time, since the surface of the pixel electrode and the surface of the insulator substantially match,
The step formed in the gap between the pixel electrodes is almost completely flattened.

Therefore, various problems such as poor alignment of the liquid crystal material due to the above-mentioned step portion and lowering of contrast due to irregular reflection of incident light can be solved. Thereby, it is possible to realize a reflection type LCD having high definition display performance.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining an outline of the present invention.

FIG. 2 is a view showing a manufacturing process of a conventional active matrix substrate.

FIG. 3 is a diagram showing a manufacturing process of a reflective LCD.

FIG. 4 is a diagram showing a manufacturing process of a reflective LCD.

FIG. 5 is a diagram of the active matrix substrate as viewed from above.

FIG. 6 is a diagram illustrating a structure of an active matrix substrate.

FIG. 7 is a diagram showing a structure of an active matrix substrate.

FIG. 8 is a diagram showing a configuration of a three-panel projector.

FIG. 9 illustrates an example of an applied product.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 101 Glass substrate 102, 103 Pixel TFT 104 Metal thin film 105 Resist mask 106 Exposed part 107 Anodic oxide 108, 109 Pixel electrode

Claims (22)

[Claims] 1. A plurality of electrodes are formed on a substrate having an insulating surface, and the plurality of electrodes are insulated and separated from each other by an oxide containing a material constituting the electrodes as a main component. Semiconductor device. 2. The semiconductor device according to claim 1, wherein said plurality of electrodes are made of an anodizable material. 3. The semiconductor device according to claim 1, wherein the material forming the plurality of electrodes is aluminum or a material containing aluminum as a main component, and the oxide is alumina. 4. The method according to claim 1, further comprising: a first substrate, a second substrate having a light-transmitting property, and a liquid crystal layer sandwiched between the first substrate and the second substrate. The substrate and the second substrate are formed with stripe-shaped electrodes. The stripe-shaped electrodes formed on the first substrate are made of an oxide containing a material constituting the electrodes as a main component. A semiconductor device characterized by being insulated from each other. 5. The semiconductor device according to claim 4, wherein the stripe-shaped electrodes formed on the first substrate are made of a material that can be anodized. 6. The method according to claim 4, wherein the stripe-shaped electrode formed on the first substrate is made of aluminum or a material mainly containing aluminum, and the oxide is made of alumina. Semiconductor device. 7. The plurality of pixels, comprising: at least: a plurality of semiconductor elements formed in a matrix on a substrate having an insulating surface; and a plurality of pixel electrodes connected to each of the plurality of semiconductor elements. A semiconductor device, wherein the electrodes are insulated and separated from each other by an oxide containing a material constituting the pixel electrode as a main component. 8. A substrate having at least a plurality of semiconductor elements formed in a matrix and a plurality of pixel electrodes connected to each of the plurality of semiconductor elements, and a liquid crystal layer held on the substrate. A semiconductor device, wherein the plurality of pixel electrodes are insulated from each other by an oxide containing a material constituting the pixel electrodes as a main component. 9. The semiconductor device according to claim 8, wherein the material forming the pixel electrode is a material that can be anodized. 10. A semiconductor device comprising: a substrate having a plurality of semiconductor elements formed in a matrix and a plurality of pixel electrodes connected to each of the plurality of semiconductor elements; and a liquid crystal layer held on the substrate. A semiconductor device, wherein the plurality of pixel electrodes are made of aluminum or a material containing aluminum as a main component, and are insulated from each other by an oxide containing aluminum as a main component. 11. The semiconductor device according to claim 8, wherein the liquid crystal layer is sandwiched between the substrate and a counter substrate facing the substrate. 12. The semiconductor device according to claim 8, wherein said oxide is alumina. 13. The semiconductor device according to claim 8, wherein said semiconductor element is a thin film transistor. 14. A step of forming a metal thin film on a substrate having an insulating surface, a step of selectively forming a resist mask on the metal thin film, and oxidizing an exposed portion of the metal thin film using the resist mask as a mask. And a step of transforming the exposed portion to an oxide, wherein the metal thin film is insulated and separated into a plurality by the oxide. 15. A semiconductor device including at least a first substrate, a second substrate having a light-transmitting property, and a liquid crystal layer sandwiched between the first substrate and the second substrate. Forming a metal thin film on the first substrate, selectively forming a resist mask on the metal thin film, and oxidizing an exposed portion of the metal thin film using the resist mask as a mask. And a step of transforming the exposed portion into an oxide, wherein the metal thin film is insulated and separated in a stripe shape by the oxide. 16. A step of forming a plurality of semiconductor elements on a substrate having an insulating surface, a step of forming a metal thin film electrically connected to the plurality of semiconductor elements, and selectively forming a resist on the metal thin film. Forming a mask; and oxidizing an exposed portion of the metal thin film using the resist mask as a mask to transform the exposed portion into an oxide, wherein the oxide forms the metal thin film in a matrix. A method for manufacturing a semiconductor device, comprising insulating and separating. 17. A semiconductor device comprising: a substrate having a plurality of semiconductor elements formed in a matrix and a plurality of pixel electrodes connected to each of the plurality of semiconductor elements; and a liquid crystal layer held on the substrate. A method for manufacturing a semiconductor device, comprising: a step of forming a metal thin film electrically connected to the plurality of semiconductor elements; a step of selectively forming a resist mask on the metal thin film; and using the resist mask as a mask. Oxidizing an exposed portion of the metal thin film and transforming the exposed portion into an oxide; and isolating and separating the metal thin film in a matrix by the oxide. . 18. The method for manufacturing a semiconductor device according to claim 17, wherein the liquid crystal layer is sandwiched between the substrate and a counter substrate facing the substrate. 19. The method according to claim 16, wherein
The method for manufacturing a semiconductor device, wherein the semiconductor element is a thin film transistor. 20. The method for manufacturing a semiconductor device according to claim 14, wherein the metal thin film is a material that can be anodized. 21. The method for manufacturing a semiconductor device according to claim 14, wherein the metal thin film is made of aluminum or a material containing aluminum as a main component. 22. The method according to claim 14, wherein the oxide is formed by an anodic oxidation method.