US20080198315A1 - Liquid crystal display device and method of fabricating the same - Google Patents
Liquid crystal display device and method of fabricating the same Download PDFInfo
- Publication number
- US20080198315A1 US20080198315A1 US12/076,475 US7647508A US2008198315A1 US 20080198315 A1 US20080198315 A1 US 20080198315A1 US 7647508 A US7647508 A US 7647508A US 2008198315 A1 US2008198315 A1 US 2008198315A1
- Authority
- US
- United States
- Prior art keywords
- electrically insulating
- insulating film
- substrate
- liquid crystal
- electrode
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Images
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/133345—Insulating layers
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/136—Liquid crystal cells structurally associated with a semi-conducting layer or substrate, e.g. cells forming part of an integrated circuit
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
- G02F1/133553—Reflecting elements
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/136—Liquid crystal cells structurally associated with a semi-conducting layer or substrate, e.g. cells forming part of an integrated circuit
- G02F1/1362—Active matrix addressed cells
- G02F1/136227—Through-hole connection of the pixel electrode to the active element through an insulation layer
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/136—Liquid crystal cells structurally associated with a semi-conducting layer or substrate, e.g. cells forming part of an integrated circuit
- G02F1/1362—Active matrix addressed cells
- G02F1/136231—Active matrix addressed cells for reducing the number of lithographic steps
- G02F1/136236—Active matrix addressed cells for reducing the number of lithographic steps using a grey or half tone lithographic process
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/136—Liquid crystal cells structurally associated with a semi-conducting layer or substrate, e.g. cells forming part of an integrated circuit
- G02F1/1362—Active matrix addressed cells
- G02F1/1368—Active matrix addressed cells in which the switching element is a three-electrode device
Abstract
A liquid crystal display device including a first substrate, a second substrate facing and spaced away from the first substrate, a liquid crystal layer sandwiched between the first and second substrates, a switching device formed on the first substrate, a first electrically insulating film randomly patterned on the first substrate, a second electrically insulating film covering the first electrically insulating film therewith, and having a wavy surface, and a reflection electrode formed on the second electrically insulating film, and electrically connected to an electrode of the switching device, wherein a light passing through the second substrate and the liquid crystal layer is reflected at the reflection electrode, and the second electrically insulating film extends outwardly from the first electrically insulating film by a certain length at an end of a display region in which images are to be displayed, such that a step formed by the first and second electrically insulating films in the vicinity of the end of the display region is smoothed.
Description
- This application is a division of co-pending application Ser. No. 11/178,463 filed Jul. 12, 2005, which is a division of application Ser. No. 10/059,183 filed on Jan. 31, 2002, the entire contents of which are hereby incorporated by reference.
- 1. Field of the Invention
- The invention relates to a liquid crystal display device and a method of fabricating the same.
- 2. Description of the Related Art
- A reflection type liquid crystal display device reflects an incident light at a reflection electrode formed therein towards a viewer. Accordingly, a reflection type liquid crystal display device is not necessary to include a light source such as a back light device, and thus, consumes less power and can be fabricated thinner and lighter than a light-transmission type liquid crystal display device. A reflection type liquid crystal display device is used mainly in a handy communication terminal.
- Hereinbelow is explained a conventional reflection type liquid crystal display device with reference to
FIG. 1 which is a plan view of a conventional reflection type liquid crystal display device,FIG. 2 which is a cross-sectional view taken along the line II-II inFIG. 1 , andFIGS. 3A to 3H which are cross-sectional views each illustrating a step of a method of fabricating a substrate on which a thin film transistor (TFT) is to be fabricated.FIG. 1 illustrates pixels located at an outer periphery of a display area in which images are to be displayed. Electrode terminals and other parts are formed in areas located at upper and left sides of the illustrated pixels, outside the display area. - First, a structure of a conventional reflection type liquid crystal display device is explained hereinbelow with reference to
FIGS. 1 and 2 . - The illustrated conventional reflection type liquid crystal display device is comprised of a
TFT substrate 5 on which a thin film transistor (TFT) is formed, anopposing substrate 6 facing and spaced away from theTFT substrate 5, and a liquidcrystal display layer 4 sandwiched between theTFT substrate 5 and theopposing substrate 6. - The
TFT substrate 5 is comprised ofgate lines 1,drain lines 2 extending perpendicularly to thegate lines 1, switching devices each comprised of athin film transistor 3 formed in each of pixel areas defined by thegate lines 1 and thedrain lines 2, areflection electrode 18 which reflects a light entering the pixel areas and applies a voltage to liquid crystal molecules in theliquid crystal layer 4, a first electrically insulatingfilm 16 formed on theTFT substrate 5, and a second electrically insulatingfilm 17 which cooperates with the first electrically insulatingfilm 16 to present a wavy surface to thereflection electrode 18. - The
thin film transistor 3 has agate electrode 11 electrically connected to thegate line 1, adrain electrode 14 electrically connected to thedrain line 2, and asource electrode 15 electrically connected to thereflection electrode 18. - As illustrated in
FIG. 2 , theTFT substrate 5 is comprised further of afirst substrate 10 on which thegate electrode 11 is formed, a gateinsulating film 12 formed entirely on thefirst substrate 10, anamorphous silicon layer 13 a formed on thegate insulating film 12, and n+amorphous silicon layers 13 b formed on theamorphous silicon layer 13 a. - The
drain electrode 14 and thesource electrode 15 extend covering both the n+amorphous silicon layers 13 b and thegate insulating film 12 therewith. - The first electrically insulating
film 16 is randomly formed in each of pixels in the display area, and is covered with the second electrically insulatingfilm 17 to smooth steps formed by the first electrically insulatingfilm 16. Thereflection electrode 18 has a wave surface showing a certain optical reflection characteristic, reflecting a wavy surface of the second electrically insulatingfilm 17. - As illustrated in
FIG. 2 , thereflection electrode 18 is electrically connected to thesource electrode 15 at acontact hole 19. - The
opposing substrate 6 is comprised of asecond substrate 20, acolor filter 21 formed on a first surface of thesecond substrate 20, acommon electrode 22 through which a voltage is applied to liquid crystal molecules in theliquid crystal layer 4, and a polarizingplate 23 formed on a second surface of thesecond substrate 20. - Liquid crystal molecules in the
liquid crystal layer 4 are controlled by a voltage applied across theTFT substrate 5 and theopposing substrate 6. - An
incident light 24 passing through theopposing substrate 6 and theliquid crystal layer 4 is reflected at thereflection electrode 18 having the wavy surface, and then, passes again through theliquid crystal layer 4 and theopposing substrate 6, and leaves the liquid crystal display device as an out-goinglight 25. - In the conventional liquid crystal display device, steep steps formed by the first electrically insulating
film 16 randomly formed on theTFT substrate 5 are smoothed by the second electrically insulatingfilm 17 thinner than the first electrically insulatingfilm 16, as mentioned earlier. As a result, thereflection electrode 18 has a sufficiently wavy surface at which theincident light 24 is randomly reflected, ensuring that images can be displayed on a screen with uniform brightness. - Hereinbelow is explained a method of fabricating the
TFT substrate 5 in the above-mentioned conventional liquid crystal display device with reference toFIGS. 3A to 3H . Thethin film transistor 3 acting as a switching device has a reverse-stagger structure. - First, as illustrated in
FIG. 3A , thegate electrode 11 and thegate line 1 are formed on thefirst substrate 10. Then, thegate insulating film 12 is formed on thefirst substrate 10, covering thegate electrode 11 therewith. Then, theamorphous silicon layer 13 a is formed on thegate insulating film 12 above thegate electrode 11, and subsequently, the n+amorphous silicon layer 13 b is formed on theamorphous silicon layer 13 a. - Then, the
drain electrode 14 and thesource electrode 15 are formed partially covering the n+amorphous silicon layer 13 b therewith and further partially covering thegate insulating film 12 therewith. - Then, the n+
amorphous silicon layers 13 b is etched in its exposed area with the drain andsource electrodes thin film transistor 3. Then, thethin film transistor 3 is covered with a passivation film (not illustrated). - Then, as illustrated in
FIG. 3B , the first electrically insulatingfilms 16 composed of a resin are randomly formed in each of pixel regions. The electrically insulatingfilms 16 are formed to have a thickness equal to or greater than a predetermined thickness in order to provide appropriate optical reflection characteristic to thereflection electrode 18. - Then, as illustrated in
FIG. 3C , the first electrically insulatingfilms 16 are heated to turn their sharp corners into rounded corners. - Then, as illustrated in
FIG. 3D , the first electricallyinsulating films 16 are covered with the second electrically insulatingfilm 17. Since the second electrically insulatingfilm 17 is formed in order to smooth steps formed by the first electrically insulatingfilms 16, if it is too thin, the steps formed by the first electrically insulatingfilms 16 remain as they are, and if it is too thick, the second electrically insulatingfilm 17 would have a planar surface. Hence, a thickness of the second electrically insulatingfilm 17 is determined taking the optical reflection characteristic of thereflection electrode 18 into consideration. - Then, the second electrically insulating
film 17 is removed in an area outside the display area, and concurrently removed partially above thesource electrode 15 to form thecontact hole 19 through which thereflection electrode 18 is electrically connected to thesource electrode 15. - Then, as illustrated in
FIG. 3E , ametal 18 b having high reflectivity is deposited all over thefirst substrate 10. - Then, as illustrated in
FIG. 3F , themetal 18 b is entirely covered with aresist 26. - Then, as illustrated in
FIG. 3G , theresist 26 is exposed to a light and subsequently developed such that aresist pattern 26 a covers only an area in which thereflection electrode 18 is to be formed. Then, themetal 18 b is etched for removal with theresist pattern 26 being used as a mask. - Thus, as illustrated in
FIG. 3H , thereflection electrode 18 composed of themetal 18 b is formed covering the second electrically insulatingfilm 17 therewith. Then, theresist pattern 26 a is removed. - The
resultant reflection electrode 18 is electrically connected to thesource electrode 15 in each of pixels. Thereflection electrode 18 is removed at a boundary between pixel areas, that is, on both thegate line 1 and thedrain line 2, and further in an area (an area located at the left inFIG. 3H ) where electrode terminals are to be formed which area is outside the display area, in order that thereflection electrode 18 acts as a pixel electrode to apply a voltage to liquid crystal molecules in theliquid crystal layer 4. - However, the above-mentioned conventional liquid crystal display device and the above-mentioned method of fabricating the same are accompanied with the following problems.
- In the step having been explained with reference to
FIG. 3D , the second electrically insulatingfilm 17 formed for smoothing the steps formed by the first electrically insulatingfilms 16 is formed also on both thegate line 1 and thedrain line 2 between adjacent pixels, in order to make it easy to remove thereflection electrode 18. In the area (which is located at the left inFIG. 3H ) where electrode terminals are to be formed, located outside the display area, the second electrically insulatingfilm 17 is removed at the same location as the first electrically insulatingfilm 16, in order to render the area as small as possible and thereby fabricate a liquid crystal display device in a small size. As a result, as illustrated inFIG. 3H , the first and second electrically insulatingfilms - Herein, it is assumed that the resist 26 is deposited entirely over the
first substrate 10 with the first and second electrically insulatingfilm film 17 covers the first electrically insulatingfilm 16 therewith to thereby have a smooth upper surface, that is, in pixels or on thegate line 1 and thedrain line 2 between adjacent pixels. In contrast, in the area where electrode terminals are to be formed, located outside the display area, the resist 26 would gather due to the steep cross-section, and resultingly, would have a thickness greater than a designed thickness. - Since the conditions for carrying out exposure of the resist 26 to a light and development of the resist 26 are determined based on a resist existing between pixels which resist is required to be exactly patterned, the resist 26 could not be completely removed at an end of the first and second electrically insulating
films residue 26 b, as illustrated inFIG. 3G . - The resist
residue 26 b would prevent themetal 18 b existing therebelow from being etched, resulting in annon-removed portion 18 a of themetal 18 b, as illustrated inFIG. 3H . - If the
portion 18 a of themetal 18 b remains not removed in an area where themetal 18 b has to be all removed, as mentioned above and as illustrated inFIG. 3H , there would be unintentionally generated a parasitic capacity between thenon-removed portion 18 a and the gate anddrain lines - As an alternative, if the
non-removed portion 18 a of themetal 18 b bridges over adjacent pixels, there would be caused a problem that theresultant reflection electrode 18 falls into short-circuit. - In view of the above-mentioned problems in the conventional liquid crystal display device and the method of fabricating the same, it is an object of the present invention to provide a liquid crystal display device and a method of fabricating the same both of which are capable of preventing unintentional generation of a parasitic capacity caused by a non-removed portion of a reflection electrode and further preventing a reflection electrode from falling into short-circuit between adjacent pixels.
- In one aspect of the present invention, there is provided a liquid crystal display device including (a) a first substrate, (b) a second substrate facing and spaced away from the first substrate, (c) a liquid crystal layer sandwiched between the first and second substrates, (d) a switching device formed on the first substrate, (e) a first electrically insulating film randomly patterned on the first substrate, (f) a second electrically insulating film covering the first electrically insulating film therewith, and having a wavy surface, and (g) a reflection electrode formed on the second electrically insulating film, and electrically connected to an electrode of the switching device, wherein a light passing through the second substrate and the liquid crystal layer is reflected at the reflection electrode, the second electrically insulating film extends outwardly from the first electrically insulating film by a certain length at an end of a display region in which images are to be displayed, such that a step formed by the first and second electrically insulating films in the vicinity of the end of the display region is smoothed.
- It is preferable that the certain length is in the range of about 10 μm to about 12 μm both inclusive.
- It is preferable that the second electrically insulating film has a thickness in the range of about 0.3 μm to about 1.5 μm both inclusive.
- It is preferable that the first electrically insulating film has a thickness in the range of about 1 μm to about 3 μm both inclusive.
- For instance, the second electrically insulating film may be composed of thermo-flexible organic or inorganic material.
- For instance, the first and second electrically insulating films may be composed of different materials from each other.
- For instance, the first and second electrically insulating films may be composed of the same material having different viscosities from each other.
- For instance, the first and second electrically insulating films may be composed of a combination of organic and inorganic materials.
- There is further provided a liquid crystal display device including (a) a first substrate, (b) a second substrate facing and spaced away from the first substrate, (c) a liquid crystal layer sandwiched between the first and second substrates, (d) a switching device formed on the first substrate, (e) a first electrically insulating film randomly patterned on the first substrate, (f) a second electrically insulating film covering the first electrically insulating film therewith, and having a wavy surface, and (g) a reflection electrode formed on the second electrically insulating film, and electrically connected to an electrode of the switching device, wherein a light passing through the second substrate and the liquid crystal layer is reflected at the reflection electrode, the second electrically insulating film extends inwardly from the first electrically insulating film by a certain length at a contact region where the reflection electrode is electrically connected to the electrode of the switching device, such that a step formed by the first and second electrically insulating films in the vicinity of the contact region is smoothed.
- There is still further provided a liquid crystal display device including (a) a first substrate, (b) a second substrate facing and spaced away from the first substrate, (c) a liquid crystal layer sandwiched between the first and second substrates, (d) a switching device formed on the first substrate, (e) an electrically insulating film formed on the first substrate, and defined by a thick region and a thin region, the electrically insulating film having a wavy surface, and (f) a reflection electrode formed on the electrically insulating film, and electrically connected to an electrode of the switching device, wherein a light passing through the second substrate and the liquid crystal layer is reflected at the reflection electrode, the thin region extends outwardly from the thick region by a certain length at an end of a display region in which images are to be displayed, such that a step formed by the electrically insulating film in the vicinity of the end of the display region is smoothed.
- There is yet further provided a liquid crystal display device including (a) a first substrate, (b) a second substrate facing and spaced away from the first substrate, (c) a liquid crystal layer sandwiched between the first and second substrates, (d) a switching device formed on the first substrate, (e) an electrically insulating film formed on the first substrate, and defined by a thick region and a thin region, the electrically insulating film having a wavy surface, and (f) a reflection electrode formed on the electrically insulating film, and electrically connected to an electrode of the switching device, wherein a light passing through the second substrate and the liquid crystal layer is reflected at the reflection electrode, the thin region extends inwardly from the thick region by a certain length at a contact region where the reflection electrode is electrically connected to the electrode of the switching device, such that a step formed by the electrically insulating film in the vicinity of the contact region is smoothed.
- In another aspect of the present invention, there is provided a method of fabricating a liquid crystal display device, including the steps at least of (a) randomly patterning a first electrically insulating film on a first substrate on which a switching device is fabricated, (b) covering the first electrically insulating film with a second electrically insulating film, and (c) forming a reflection electrode on a wavy surface of the first and second electrically insulating films such that the reflection electrode is electrically connected to an electrode of the switching device, the reflection electrode reflecting a light passing through both a second substrate facing and spaced away from the first substrate and a liquid crystal layer sandwiched between the first and second substrates, the step (b) including (b1) forming the second electrically insulating film over the first substrate such that the first electrically insulating film is entirely covered with the second electrically insulating film, and (b2) partially removing the second electrically insulating film such that the second electrically insulating film extends outwardly from the first electrically insulating film by a certain length at an end of a display region in which images are to be displayed, thereby a step formed by the first and second electrically insulating films in the vicinity of the end of the display region is smoothed.
- It is preferable that the step (c) includes the steps of (c1) depositing a material of which the reflection electrode is composed, entirely over the second electrically insulating film, (c2) coating a resist over the material, (c3) removing the resist in an area in which the material is to be removed, and (c4) etching the material with the resist being used as a mask.
- There is further provided a method of fabricating a liquid crystal display device, including the steps at least of (a) randomly patterning a first electrically insulating film on a first substrate on which a switching device is fabricated, (b) covering the first electrically insulating film with a second electrically insulating film, and (c) forming a reflection electrode on a wavy surface of the first and second electrically insulating films such that the reflection electrode is electrically connected to an electrode of the switching device, the reflection, electrode reflecting a light passing through both a second substrate facing and spaced away from the first substrate and a liquid crystal layer sandwiched between the first and second substrates, the step (b) including (b1) forming the second electrically insulating film over the first substrate such that the first electrically insulating film is entirely covered with the second electrically insulating film, and (b2) partially removing the second electrically insulating film such that the second electrically insulating film extends inwardly from the first electrically insulating film by a certain length at a contact region where the reflection electrode is electrically connected to the electrode of the switching device, thereby a step formed by the first and second electrically insulating films in the vicinity of the contact region is smoothed.
- It is preferable that the step (c) includes the steps of (c1) depositing a material of which the reflection electrode is composed, entirely over the second electrically insulating film, (c2) coating a resist over the material, (c3) removing the resist in an area in which the material is to be removed, and (c4) etching the material with the resist being used as a mask.
- There is still further provided a method of fabricating a liquid crystal display device, including the steps at least of (a) randomly patterning an electrically insulating film on a first substrate on which a switching device is fabricated, the electrically insulating film having a wavy surface, and (b) forming a reflection electrode on the wavy surface of the electrically insulating film such that the reflection electrode is electrically connected to an electrode of the switching device, the reflection electrode reflecting a light passing through both a second substrate facing and spaced away from the first substrate and a liquid crystal layer sandwiched between the first and second substrates, the step (b) including (b1) forming the electrically insulating film over the first substrate, and (b2) patterning the electrically insulating film into a removal region in which the electrically insulating film is completely removed, a thin region in which the electrically insulating film remains as a thin film, and a thick region in which the electrically insulating film remains as a thick film such that the thin region extends outwardly from the thick region by a certain length at an end of a display region in which images are to be displayed, thereby a step formed by the electrically insulating film in the vicinity of the end of the display region is smoothed.
- It is preferable that the electrically insulating film is patterned in the step (b2) in single exposure to a light through the use of a half-tone mask having a light-permeable portion for defining the removal region, a half-light-permeable portion for defining the thin region, and a light-impermeable portion for defining the thick region.
- It is preferable that the half-light-permeable portion is located adjacent to the light-permeable portion.
- It is preferable that the electrically insulating film is patterned in the step (b2) in single exposure to a light through the use of a photo mask having a light-permeable portion for defining the removal region, and a half-light-permeable portion for defining the thin region.
- It is preferable that the electrically insulating film is patterned in the step (b2) in single exposure to a light through the use of a photo mask having such a fine pattern that a light to be directed to the thin region is attenuated.
- There is yet further provided a method of fabricating a liquid crystal display device, including the steps at least of (a) randomly patterning an electrically insulating film on a first substrate on which a switching device is fabricated, the electrically insulating film having a wavy surface, and (b) forming a reflection electrode on the wavy surface of the electrically insulating film such that the reflection electrode is electrically connected to an electrode of the switching device, the reflection electrode reflecting a light passing through both a second substrate facing and spaced away from the first substrate and a liquid crystal layer sandwiched between the first and second substrates, the step (b) including (b1) forming the electrically insulating film over the first substrate, and (b2) patterning the electrically insulating film into a removal region in which the electrically insulating film is completely removed, a thin region in which the electrically insulating film remains as a thin film, and a thick region in which the electrically insulating film remains as a thick film such that the thin region extends inwardly from the thick region by a certain length at a contact region where the reflection electrode is electrically connected to the electrode of the switching device, thereby a step formed by the electrically insulating film in the vicinity of the contact region is smoothed.
- The advantages obtained by the aforementioned present invention will be described hereinbelow.
- In accordance with the present invention, the second electrically insulating film is designed to extend outwardly from the first electrically insulating film by a certain length at an end of a display region, and is further designed to have a thickness in a predetermined range. As an alternative, the second electrically insulating film is designed to extend inwardly from the first electrically insulating film by a certain length at a contact region. As a result, it would be possible to smooth a step formed by the first and second electrically insulating films in the vicinity of an end of the display region. This ensures that it would be possible to prevent a resist used for patterning the reflection electrode from gathering as a resist residue at an end of the first and second electrically insulating films. Thus, generation of an non-removed portion of a reflection electrode caused by the resist residue would be prevented, ensuring that it would be possible to avoid an unintentional parasitic capacity and prevent adjacent pixels from short-circuiting with each other. As a result, the present invention provides a liquid crystal display device having no non-uniformity in display and presenting high quality images.
- Furthermore, the use of a half-tone mask or photo mask in the method of fabricating a liquid crystal display device would make it possible to form the first and second electrically insulating films of a common material in a single step, ensuring reduction in the number of fabrication steps.
- The above and other objects and advantageous features of the present invention will be made apparent from the following description made with reference to the accompanying drawings, in which like reference characters designate the same or similar parts throughout the drawings.
-
FIG. 1 is a plan view of a conventional reflection type liquid crystal display device. -
FIG. 2 is a cross-sectional view taken along the line II-II inFIG. 1 . -
FIGS. 3A to 3H are cross-sectional views each illustrating a step of a method of fabricating a substrate on which a thin film transistor (TFT) is to be fabricated, in the conventional reflection type liquid crystal display device illustrated inFIG. 1 . -
FIG. 4 is a plan view of the reflection type liquid crystal display device in accordance with the first embodiment of the present invention. -
FIG. 5 is a cross-sectional view taken along the line V-V inFIG. 4 . -
FIGS. 6A to 6H are cross-sectional views each illustrating a step of a method of fabricating a substrate on which a thin film transistor (TFT) is to be fabricated, in the reflection type liquid crystal display device illustrated inFIG. 4 . -
FIG. 7 is a graph showing a relation between a thickness of a resist and light exposure in the reflection type liquid crystal display device in accordance with the first embodiment. -
FIG. 8 is a graph showing a relation between a thickness of an electrically insulating film at a periphery of the display area and a thickness of a resist in the reflection type liquid crystal display device in accordance with the first embodiment. -
FIG. 9 is a graph showing a relation among a viscosity of a resin, a number of revolution in spin-coating a resin and a thickness in the reflection type liquid crystal display device in accordance with the first embodiment. -
FIGS. 10A to 10H are cross-sectional views each illustrating a step of a method of fabricating a substrate on which a thin film transistor (TFT) is to be fabricated, in the reflection type liquid crystal display device in accordance with the second embodiment of the present invention. - Preferred embodiments in accordance with the present invention will be explained hereinbelow with reference to drawings.
-
FIG. 4 is a plan view of a reflection type liquid crystal display device in accordance with the first embodiment, andFIG. 5 is a cross-sectional view taken along the line V-V inFIG. 4 . - With reference to
FIGS. 4 and 5 , the reflection type liquid crystal display device is comprised of aTFT substrate 5 on which a thin film transistor (TFT) is formed, an opposingsubstrate 6 facing and spaced away from theTFT substrate 5, and a liquidcrystal display layer 4 sandwiched between theTFT substrate 5 and the opposingsubstrate 6. - The
TFT substrate 5 is comprised ofgate lines 1,drain lines 2 extending perpendicularly to thegate lines 1, switching devices each comprised of athin film transistor 3 formed in each of pixel areas defined by thegate lines 1 and thedrain lines 2, areflection electrode 18 which reflects a light entering the pixel areas and applies a voltage to liquid crystal molecules in theliquid crystal layer 4, a first electrically insulatingfilm 16 formed on theTFT substrate 5, and a second electrically insulatingfilm 17 which cooperates with the first electrically insulatingfilm 16 to present a wavy surface to thereflection electrode 18. - The
thin film transistor 3 has agate electrode 11 electrically connected to thegate line 1, adrain electrode 14 electrically connected to thedrain line 2, and asource electrode 15 electrically connected to thereflection electrode 18. - As illustrated in
FIG. 5 , theTFT substrate 5 is comprised further of afirst substrate 10 on which thegate electrode 11 is formed, agate insulating film 12 formed entirely on thefirst substrate 10, anamorphous silicon layer 13 a formed on thegate insulating film 12, and n+ amorphous silicon layers 13 b formed on theamorphous silicon layer 13 a. - The
drain electrode 14 and thesource electrode 15 extend covering both the n+ amorphous silicon layers 13 b and thegate insulating film 12 therewith. - The first electrically insulating
film 16 is randomly formed in each of pixels in the display area, and is covered with the second electrically insulatingfilm 17 to smooth steps formed by the first electrically insulatingfilm 16. - The first electrically insulating
film 16 is randomly formed in the display area in order to have uniform optical reflection characteristic all over the display area, whereas the firstelectrically film 16 is not formed in a terminal area located outside the display area, because electrode terminals and other parts have to be formed in the terminal area. InFIG. 4 , the terminal area extends at the upper and left sides of the illustrated pixels. - The second electrically insulating
film 17 is continuously formed in the display area without acontact hole 19, and slightly extends to the terminal area such that an end of the first electrically insulatingfilm 16 does not overlap an end of the second electrically insulatingfilm 17. This ensures that the display area has a smooth step at an end thereof. - As illustrated in
FIG. 5 , thereflection electrode 18 is electrically connected to thesource electrode 15 at thecontact hole 19 formed through the second electrically insulatingfilm 17 above thesource electrode 15. - The
reflection electrode 18 is necessary to be separated into pieces for each of pixels, because thereflection electrode 18 acts also as a pixel electrode for applying a voltage to liquid crystal molecules in theliquid crystal layer 4. Hence, as illustrated inFIG. 4 , thereflection electrode 18 is separated along thegate lines 1 and thedrain lines 2 for each of pixels. - The opposing
substrate 6 is comprised of asecond substrate 20, acolor filter 21 formed on a first surface of thesecond substrate 20, acommon electrode 22 through which a voltage is applied to liquid crystal molecules in theliquid crystal layer 4, and apolarizing plate 23 formed on a second surface of thesecond substrate 20. - Liquid crystal molecules in the
liquid crystal layer 4 are controlled by a voltage applied across theTFT substrate 5 and the opposingsubstrate 6. - An incident light 24 passing through the opposing
substrate 6 and theliquid crystal layer 4 is reflected at thereflection electrode 18 having the wavy surface, and then, passes again through theliquid crystal layer 4 and the opposingsubstrate 6, and leaves the liquid crystal display device as an out-goinglight 25. - The
reflection electrode 18 has a wave surface reflecting a wavy surface of the second electrically insulatingfilm 17, and has an optical reflection characteristic defined by angles of raised and recessed portions of the wave surface of thereflection electrode 18. Hence, the angles of the raised and recessed portions of the wave surface of thereflection electrode 18 are determined so as to provide a desired optical reflection characteristic to thereflection electrode 18. For instance, the raised and recessed portions may be defined by two or more of a pitch between raised portion, a pitch between recessed portions, a height of a raised portion, and a depth of a recessed portion. - A lower limit of a thickness of the first electrically insulating
film 16 is defined by the above-mentioned optical reflection characteristic, and further by a parasitic capacity. If the first electrically insulatingfilm 16 is formed too thin, it would not be possible to significantly change a direction of reflection of theincident light 24, and a space between thereflection electrode 18 and the gate anddrain lines reflection electrode 18 and the gate anddrain lines - From the above-mentioned standpoints, the first electrically insulating
film 16 is preferably designed to have a thickness in the range of about 1 μm to about 3 μm. - Since the second electrically insulating
film 17 is formed for moderately relaxing the raised and recessed portions of the first electrically insulatingfilm 16 to smooth the wavy surface of the first electrically insulatingfilm 16, if the second electrically insulatingfilm 17 is too thin, the second electrically insulatingfilm 17 could not smooth the wavy surface of the first electrically insulatingfilm 16, whereas if the second electrically insulatingfilm 17 is too thick, the second electrically insulatingfilm 17 would cancel projections and recesses of the first electrically insulatingfilm 16, and would be flattened. - In the first embodiment, the second electrically insulating
film 17 is designed to have such a thickness that resist residue does not remain non-removed in an area outside the display area. In accordance with the results of the experiments having been conducted by the inventors, it has been found out that it is preferable for the second electrically insulatingfilm 17 to have a thickness in the range of about 0.3 μm to about 1.5 μm, and a distance between an end of the first electrically insulatingfilm 16 to an end of the second electrically insulatingfilm 17 is preferably in the range of about 10 μm to about 12 μm. - Hereinbelow is explained the reason of selecting the above-mentioned figures, with reference to
FIGS. 7 to 9 . -
FIG. 7 shows a relation between a thickness of a resist and light exposure necessary for removing the resist,FIG. 8 illustrates a positional relation between thicknesses of the first electrically insulatingfilm 16, the second electrically insulatingfilm 17 and the resist 26, and locations of ends of those, andFIG. 9 shows a relation among a viscosity of a resin, a thickness of a resin and a number of revolution for spin-coating. - As illustrated in
FIG. 7 , greater light exposure is necessary for removing a thicker resist. An accuracy with which a resist having a certain thickness is patterned is controllable for a certain range of light exposure. In other words, the accuracy can be controlled in the certain range of light exposure, though a pattern might be slightly thicker or thinner than designed. For instance, when a resist having a thickness of 1 m is to be patterned, optimal light exposure is about 140 mJ/cm2. However, an accuracy with which the resist is patterned can be controlled, if light exposure is in the range of about 80 mJ/cm2 to about 190 mJ/cm2. - Conversely speaking, a thickness of a resist which can be patterned by certain light exposure has a certain range. If a light is exposed to a resist by 190 mJ/cm2, a resist having a thickness of 1 μm can be accurately patterned, and further, a resist having a thickness of 2 μm can be accurately patterned.
- Applying the above-mentioned relation to the liquid crystal display device, a thickness of the second electrically insulating
film 17 and a distance between ends of the first and second electrically insulatingfilms reflection electrode 18 is within such a range that an accuracy with which the resist is patterned is controllable. - As illustrated in
FIG. 8 , assuming that A indicates a thickness of the first electrically insulatingfilm 16, B indicates a thickness of a planarized portion of the second electrically insulatingfilm 17, and D indicates a thickness of a raised portion of the second electrically insulatingfilm 17, a maximum variance in a thickness of the resist 26 is defined by C or equal to B. -
C=X+D+E−B−E -
- wherein X indicates a thickness of the first electrically insulating
film 16, and E indicates a thickness of thereflection electrode 18.
- wherein X indicates a thickness of the first electrically insulating
- Herein, if the resist 26 had a thickness of 2 μm which is usually selected for photolithography, as is obvious in view of
FIG. 7 , light exposure by which a resist having a thickness of 2 μm can be patterned is in the range of about 150 mJ/cm2 to about 270 mJ/cm2, and a resist having a thickness of 3.5 μm at maximum can be patterned by light exposure of 270 mJ/cm2. - Accordingly, the thickness C or B has to be equal to or smaller than 1.5 μm (3.5 μm−2 μm=1.5 μm). If the first electrically insulating
film 16 is designed to have a thickness in the range of 1 μm and 3 μm taking its optical reflection characteristic into consideration, an upper limit of a thickness of the second electrically insulatingfilm 17 is 1.5 μm, and a lower limit of a thickness of the same is preferably 0.3 μm for making a step defined by the thickness C small. - The thickness B of a planarized portion of the second electrically insulating
film 17 becomes smaller as a distance between the ends of the first and second electrically insulatingfilms film 17 is fixed, that is, about 10 μm, and more preferably equal to about 12 μm taking misregistration in a unit for exposing a resist to a light, into consideration. - In order to design the second electrically insulating
film 17 to have a thickness in the above-mentioned range, a viscosity of a resin and/or a number of revolution at which a resin is spin-coated is (are) controlled. For instance, a thickness of the second electrically insulatingfilm 17 can be accurately controlled by spin-coating a resin in accordance with the relation shown inFIG. 9 . - In order to reduce a height of the second electrically insulating film 17 (indicated as “B” in
FIG. 8 ) in the terminal area located outside the display area, an angle formed between a surface of the second electrically insulatingfilm 17 and a surface of thefirst substrate 10 might be determined to be in a certain range by improving wettability of the second electrically insulatingfilm 17 with thefirst substrate 10 or a passivation film such as a silicon nitride film. Specifically, even if the second electrically insulatingfilm 17 were thick, it would be possible to avoid the problem of resist residue by applying surface treatment such as HMDS to the second electrically insulatingfilm 17 to thereby improved the wettability, and make a contact angle small. - Thus, it would be possible to prevent resist residue from remaining non-removed on the
reflection electrode 18, by setting a thickness of the second electrically insulatingfilm 17 or a distance between the ends of the first and second electrically insulatingfilms films contact hole 19 could be controlled, ensuring that thereflection electrode 18 and thesource electrode 15 are kept in appropriate electrical contact with each other. - Hereinbelow is explained a method of fabricating the above-mentioned reflection type liquid crystal display device, with reference to
FIGS. 6A to 6H . In the method mentioned hereinbelow, thethin film transistor 3 acting as a switching device has a reverse-stagger structure. - First, a metal layer composed of chromium, for instance, is formed on the
first substrate 10 composed of glass, for instance, by sputtering. Then, the metal layer is patterned into thegate line 1 and thegate electrode 11 by photolithography and etching. The metal layer of which thegate line 1 and thegate electrode 11 are composed may be composed of a metal which has a low resistance and which can be readily patterned by photolithography, such as molybdenum, titanium, aluminum, or aluminum alloy as well as chromium. As an alternative, the metal layer may have a multi-layered structure having an aluminum layer and a barrier metal layer formed on the aluminum layer, wherein the barrier metal layer may be composed of titanium. - Then, a silicon nitride film which will make the
gate insulating film 12 is formed all over thefirst substrate 10. Then, a non-doped amorphous silicon film and a n+-doped amorphous silicon film are successively formed on thegate insulating film 12 by chemical vapor deposition (CVD). Thereafter, those amorphous silicon layers are patterned into theamorphous silicon layer 13 a and the n+amorphous silicon layer 13 b. Theamorphous silicon layer 13 a acts as an active layer in thethin film transistor 3, and the n+amorphous silicon layer 13 b ensures ohmic contact between thedrain electrode 14, thesource electrode 15 and theamorphous silicon layer 13 a. - Then, a chromium film is formed over the
amorphous silicon layer 13 a and the n+amorphous silicon layer 13 b by sputtering, and subsequently, patterned into thedrain electrode 14 and thesource electrode 15. Then, the n+amorphous silicon layer 13 b is dry-etched in an area in alignment with a space formed between thedrain electrode 14 and thesource electrode 15. This is for the purpose of preventing a current from running directly through thedrain electrode 14 and thesource electrode 15 via the n+amorphous silicon layer 13 b. - Then, a silicon nitride film is formed over the
first substrate 10 by CVD, and subsequently, patterned into a passivation film (not illustrated). The passivation film prevents impurities such as ions from diffusing into theamorphous silicon layer 13 a to thereby cause malfunction in thethin film transistor 3. - By carrying out the above-mentioned steps, the
thin film transistor 3 is fabricated in theTFT substrate 5, as illustrated inFIG. 6A . - Then, as illustrated in
FIG. 6B , the first electrically insulatingfilm 16 is formed on thegate insulating film 12 randomly in the display area. - Then, as illustrated in
FIG. 6C , a process for changing a shape is applied to the first electrically insulatingfilm 16 to thereby round the first electrically insulatingfilm 16 at corners. - Then, as illustrated in
FIG. 6D , the second electrically insulatingfilm 17 is formed entirely covering the first electrically insulatingfilm 16 therewith, and then, there is formed thecontact hole 19 throughout the second electrically insulatingfilm 17 above thesource electrode 15 for electrically connecting thereflection electrode 18 and thesource electrode 15 to each other. - The first electrically insulating
film 16 and the second electrically insulatingfilm 17 are formed entirely in the display area, and the second electrically insulatingfilm 17 is formed in such a way that the second electrically insulatingfilm 17 extends outwardly beyond the end of the first electrically insulatingfilm 16 in an area (that is, an area located at the left inFIG. 6D ) outside a pixel located at an outer periphery of the display area, thereby avoiding a steep step to be formed by the first and second electrically insulatingfilms - The first electrically insulating
film 16 may be composed of photo-insensitive resin or photosensitive resin. - If the first electrically insulating
film 16 were composed of photo-insensitive resin, the method of fabricating the liquid crystal display device would include the steps of (a) forming the first electrically insulatingfilm 16 on thefirst substrate 19, (b) forming a resist for patterning the first electrically insulatingfilm 16, (c) exposing the resist to a light, (d) developing the resist, (e) etching the first electrically insulatingfilm 16, and (e) removing the resist. - If the first electrically insulating
film 16 were composed of photo-sensitive organic or inorganic material, the method of fabricating the liquid crystal display device would include the steps of (a) forming the first electrically insulatingfilm 16 on thefirst substrate 19, (b) exposing the first electrically insulatingfilm 16 to a light, and (c) developing the first electrically insulatingfilm 16. The method may omit the steps of forming a resist for patterning the first electrically insulatingfilm 16, and removing the resist, in comparison with the method in which the first electrically insulatingfilm 16 is composed of photo-insensitive resin. - In the step having been explained with reference to
FIG. 6C , the patterned first electrically insulatingfilm 16 is molten to have rounded corners, by annealing the first electrically insulatingfilm 16 at a temperature in the range of 80 to 300 degrees centigrade. As an alternative, the first electrically insulatingfilm 16 may be molten to have rounded corners through the use of chemical instead of annealing the first electrically insulatingfilm 16. If the second electrically insulatingfilm 17 only could present a sufficiently smooth wavy surface, it would not be always necessary to apply any process to the first electrically insulatingfilm 16 to have rounded corners. - In the first embodiment, the first and second electrically insulating
films -
- Number of revolution in spin-coating: 1200 r.p.m.
- Temporarily baking temperature: 90 degrees centigrade
- Temporarily baking time: 10 minutes
- Baking temperature: 250 degrees centigrade
- Baking time: 1 hour
- The resist used for patterning the electrically insulating
films -
- Number of revolution in spin-coating: 1000 r.p.m.
- Temporarily baking temperature: 90 degrees centigrade
- Temporarily baking time: 5 minutes
- Post balking temperature (after patterning): 90 degrees centigrade
- Post baking time: 30 minutes
- The conditions for dry-etching the above-mentioned polyimide film with the patterned resist being used as a mask were as follows.
-
- Etching gas: FCl4+O2
- Gas flow ratio (FCl4/O2): 0.5-1.5
- Reaction pressure: 0.665-39.9 Pa
- Plasma power: 100-300 W
- The photolithography was carried out under ordinary resist processes.
- Though the first and second electrically insulating
films film 17 could have a desired wavy surface by composing the first and second electrically insulatingfilms film 17 could be designed to have a sufficiently smooth wavy surface, the first electrically insulatingfilm 16 might be formed by evaporation, sputtering or CVD, as well as coating. - Then, as illustrated in
FIG. 6E , ametal film 18 b composed of metal having a high reflectivity is formed entirely over the second electrically insulatingfilm 17. - Then, as illustrated in
FIG. 6F , a resist 26 is formed entirely covering themetal film 18 b. - Then, as illustrated in
FIG. 6G , the resist 26 is patterned by being exposed to a light and developed into a resistpattern 26 a covering only an area in which thereflection electrode 18 is to be formed. - Then, the
metal film 18 b is etched with the resistpattern 26 a being used as a mask. As a result, themetal film 18 b is removed in areas between adjacent pixels, specifically, above thegate line 1 and thedrain line 2, and further in the terminal area extending outside a pixel located outermost in the display area, in order to allow theresultant reflection electrode 18 to be electrically connected to thesource electrode 15 in each of pixel and act as a pixel electrode. - Thereafter, the resist
pattern 26 a is removed. Thus, there is fabricated theTFT substrate 5 as illustrated inFIG. 6H . - In the first embodiment, the
reflection electrode 18 is composed of aluminum which has high reflection ratio, and well matches with TFT process. By patterning the aluminum, theresultant reflection electrode 18 acting as a pixel electrode and a reflection plate was formed. The aluminum was wet-etched through the use of an etchant composed of mixture of phosphoric acid, acetic acid and nitric acid and heated at 60 degrees centigrade. However, it should be noted that thereflection electrode 18 might be composed any metal, if it had high reflectivity, other than aluminum. For instance, thereflection electrode 18 may be composed of silver or silver alloy which has higher reflection ratio than that of aluminum, ensuring brighter reflection performance than that of aluminum. - After alignment process was applied, the
TFT substrate 5 and the opposingsubstrate 6 were adhered to each other by applying an epoxy adhesive to marginal portions of thesubstrates film 17 formed on theTFT substrate 5 and thecommon electrode 22 formed on the opposingsubstrate 6 faced each other. Thereafter, liquid crystal was injected into a space formed between theTFT substrate 5 and the opposingsubstrate 6 to thereby form theliquid crystal layer 4. - In the above-mentioned liquid crystal display device in which the second electrically insulating
film 17 cooperates with the first electrically insulatingfilm 16 to form the wavy surface, and thereflection electrode 18 is formed on the wavy surface of the second electrically insulatingfilm 17, the second electrically insulatingfilm 17 is designed to have its end deviated from an end of the first electrically insulatingfilm 16 in the terminal area extending outside a pixel located outermost in the display area, specifically, the second electrically insulatingfilm 17 extends outwardly from an end of the first electrically insulatingfilm 16, and in addition, the second electrically insulatingfilm 17 is designed to have a thickness in the predetermined range. The above-mentioned structure of the liquid crystal display device in accordance with the first embodiment would prevent a variance in a thickness of the resist used for patterning thereflection electrode 18, and thereby, further prevent unintentional parasitic capacity and short-circuiting between adjacent pixels both caused by thenon-removed portion 18 a of the reflection electrode 18 (seeFIG. 3G ). - The
thin film transistor 3 as a switching device may be comprised of a stagger type thin film transistor or MIM diode. Even if thethin film transistor 3 is designed to have a reverse-stagger structure, the reverse-stagger structure is not to be limited to such a structure as mentioned in the first embodiment, but may have other structures. - Though each of the first and
second substrates - Hereinbelow is explained a method of fabricating a TFT substrate in the reflection type liquid crystal display device in accordance with the second embodiment, with reference to
FIGS. 10A to 10H . The second embodiment has an object of simplifying a method of fabricating a TFT substrate. Parts other than the TFT substrate in the second embodiment are fabricated in the same manner as the first embodiment. - Similarly to the first embodiment, first, a metal layer composed of chromium, for instance, is formed on the
first substrate 10 composed of glass, for instance, by sputtering. Then, the metal layer is patterned into thegate line 1 and thegate electrode 11 by photolithography and etching - Then, a silicon nitride film which will make the
gate insulating film 12 is formed all over thefirst substrate 10. Then, a non-doped amorphous silicon film and a n+-doped amorphous silicon film are successively formed on thegate insulating film 12 by CVD. Thereafter, those amorphous silicon layers are patterned into theamorphous silicon layer 13 a and the n+amorphous silicon layer 13 b. - Then, a chromium film is formed over the
amorphous silicon layer 13 a and the n+amorphous silicon layer 13 b by sputtering, and subsequently, patterned into thedrain electrode 14 and thesource electrode 15. Then, the n+amorphous silicon layer 13 b is dry-etched in an area in alignment with a space formed between thedrain electrode 14 and thesource electrode 15, to thereby form a channel region. - Then, a silicon nitride film is formed over the
first substrate 10 by CVD, and subsequently, patterned into a passivation film (not illustrated). - Thus, as illustrated in
FIG. 10A , thethin film transistor 3 is fabricated on thefirst substrate 10. - Whereas the first and second electrically insulating
films - As illustrated in
FIG. 10B , an electrically insulating and photo-sensitive film 16 a composed of organic or inorganic material is coated all over thegate insulating film 12. Similarly to the first embodiment, the electrically insulating and photo-sensitive film 16 a is comprised of a polyimide film, and coated in the following conditions. -
- Number of revolution in spin-coating: 1200 r.p.m.
- Temporarily baking temperature: 90 degrees centigrade
- Temporarily baking time: 10 minutes
- Baking temperature: 250 degrees centigrade
- Baking time: 1 hour
- The second embodiment is characterized in that a half-
tone mask 27 is used for exposing the electrically insulating and photo-sensitive film 16 a to a light, and developing the same. As illustrated inFIG. 10B , the half-tone mask 27 is designed to include a light-permeable portion 27 a through which a light can pass, a half-light-permeable portion 27 b through which a light can pass after being attenuated to some degree, and a light-impermeable portion 27 c through which a light cannot pass. The half-tone mask 27 is positioned above the electrically insulatingfilm 16 a such that the light-impermeable portion 27 c will define a raised portion, the half-light-impermeable portion 27 b will define a recessed portion, and the light-permeable portion 27 a will define an area in which the electrically insulatingfilm 16 a is entirely removed. - Then, the electrically insulating and photo-
sensitive film 16 a is exposed to a light through the half-tone mask 27, and then, developed. As a result, as illustrated inFIG. 10C , the electrically insulating and photo-sensitive film 16 a remains non-removed in an area in alignment with the light-impermeable portion 27 c, and is etched to some degree in an area in alignment with the half-light-permeable portion 27 b. Thus, the electrically insulating and photo-sensitive film 16 a has raised and recessed portions, as illustrated inFIG. 10C . - In the half-
tone mask 27, the half-light-permeable portion 27 b is designed to be located adjacent to the light-permeable portion 27 a in order for the electrically insulatingfilm 16 a not to have a steep step. - By using the half-
tone mask 27, the electrically insulatingfilm 16 a is entirely removed in an area in alignment with the light-permeable portion 27 a by being exposed to a light for a long time or being exposed to an intensive light, the electrically insulatingfilm 16 a is removed to some degree in an area in alignment with the half-light-permeable portion 27 b by being exposed to a light for a short time or being exposed to a weak light, or the electrically insulatingfilm 16 a is not removed at all in an area in alignment with the light-impermeable portion 27 c by not being exposed to a light. As a result, it would be possible to form both the first and second electrically insulatingfilms - Then, as illustrated in
FIG. 10D , a process for changing a shape is applied to the electrically insulatingfilm 16 a to thereby round the electrically insulatingfilm 16 a at corners thereof Specifically, the electrically insulatingfilm 16 a is molten to have rounded corners, by being annealed at a temperature in the range of 80 to 300 degrees centigrade. As an alternative, the electrically insulatingfilm 16 a may be molten to have rounded corners through the use of chemical instead of annealing the electrically insulatingfilm 16 a. If the electrically insulatingfilm 16 a could form the raised and recessed portions only by development, it would not be always necessary to apply any shape-changing process to the electrically insulatingfilm 16 a to have rounded corners. - Then, similarly to the first embodiment, a
metal film 18 b composed of metal having a high reflectivity is formed entirely over thefirst substrate 10, as illustrated inFIG. 10E . - Then, as illustrated in
FIG. 10F , a resist 26 is formed entirely covering themetal film 18 b. - Then, as illustrated in
FIG. 10G , the resist 26 is patterned by being exposed to a light and developed into a resistpattern 26 a covering only an area in which thereflection electrode 18 is to be formed. - Then, the
metal film 18 b is etched with the resistpattern 26 a being used as a mask. As a result, themetal film 18 b is removed in areas between adjacent pixels, specifically, above thegate line 1 and thedrain line 2, and further in the terminal area extending outside a pixel located outermost in the display area, in order to allow theresultant reflection electrode 18 to be electrically connected to thesource electrode 15 in each of pixel and act as a pixel electrode. - Thereafter, the resist
pattern 26 a is removed. Thus, there is fabricated theTFT substrate 5 as illustrated inFIG. 10H . - As mentioned above, the use of the half-
tone mask 27 would make it possible to form the electrically insulatingfilm 16 a in a single step, ensuring reduction in the number of fabrication steps in comparison with the first embodiment. - In addition, in the terminal area extending outside a pixel located outermost in the display area, the electrically insulating
film 16 a is removed to some degree in area outside an area in which the electrically insulatingfilm 16 a is not removed at all. Accordingly, the electrically insulatingfilm 16 a would not form a steep step, which ensures prevention of generation of the resistresidue 26 b, and further of unintentional generation of parasitic capacity caused by thenon-removed portion 18 a of thereflection electrode 18. - In the above-mentioned second embodiment, the electrically insulating
film 16 a has raised and recessed portions through the use of the half-tone mask 27. Instead of using the half-tone mask 27, there may be used a first mask for removing the electrically insulatingfilm 16 a only to a degree and a second mask for not removing the electrically insulatingfilm 16 a, wherein light exposure through the first and second masks are varied. As an alternative, the half-light-impermeable portion may be formed by means of a mask having a pattern smaller than an upper limit of exposure ability. As an alternative, light exposure may be varied in areas of the electrically insulatingfilm 16 a. - In the above-mentioned first and second embodiments, the second electrically insulating
film 17 is designed to have its end deviated from an end of the first electrically insulatingfilm 16 in the terminal area extending outside a pixel located outermost in the display area, specifically, the second electrically insulatingfilm 17 extends outwardly from an end of the first electrically insulatingfilm 16, and in addition, the second electrically insulatingfilm 17 is designed to have a thickness in the predetermined range. Thereby, it would be possible to prevent a variance in a thickness of the resist used for patterning thereflection electrode 18, and, further prevent unintentional parasitic capacity and short-circuiting between adjacent pixels both caused by thenon-removed portion 18 a of the reflection electrode 18 (seeFIG. 3G ). - The above-mentioned first and second embodiments may be applied to a contact area where the
reflection electrode 18 is electrically connected to thesource electrode 15 of thethin film transistor 3. Specifically, the second electrically insulatingfilm 17 is designed to extend inwardly from the first electrically insulatingfilm 16 by a certain length at the contact area. This ensures that a step formed by the first and second electrically insulatingfilms - While the present invention has been described in connection with certain preferred embodiments, it is to be understood that the subject matter encompassed by way of the present invention is not to be limited to those specific embodiments. On the contrary, it is intended for the subject matter of the invention to include all alternatives, modifications and equivalents as can be included within the spirit and scope of the following claims.
- The entire disclosure of Japanese Patent Application No. 2001-024237 filed on Jan. 31, 2001 including specification, claims, drawings and summary is incorporated herein by reference in its entirety.
Claims (5)
1. A liquid crystal display device comprising:
(a) a first substrate;
(b) a second substrate facing and spaced away from said first substrate;
(c) a liquid crystal layer sandwiched between said first and second substrates;
(d) a switching device formed on said first substrate;
(e) a first electrically insulating film randomly patterned on said first substrate;
(f) a second electrically insulating film covering said first electrically insulating film therewith, and having a wavy surface; and
(g) a reflection electrode formed on said second electrically insulating film, and electrically connected to an electrode of said switching device,
wherein a light passing through said second substrate and said liquid crystal layer is reflected at said reflection electrode,
said second electrically insulating film extends inwardly from said first electrically insulating film by a certain length at a contact region where said reflection electrode is electrically connected to said electrode of said switching device, such that a step formed by said first and second electrically insulating films in the vicinity of said contact region is smoothed.
2. The liquid crystal display device as set forth in claim 1 , wherein said certain length is in the range of about 10 μm to about 12 μm both inclusive.
3. The liquid crystal display device as set forth in claim 1 , wherein said second electrically insulating film has a thickness in the range of about 0.3 μm to about 1.5 μm both inclusive.
4. The liquid crystal display device as set forth in claim 1 , wherein said first electrically insulating film has a thickness in the range of about 1 μm to about 3 μm both inclusive.
5. The liquid crystal display device as set forth in claim 1 , wherein said second electrically insulating film is composed of thermo-flexible organic or inorganic material.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US12/076,475 US20080198315A1 (en) | 2001-01-31 | 2008-03-19 | Liquid crystal display device and method of fabricating the same |
Applications Claiming Priority (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2001-024237 | 2001-01-31 | ||
JP2001024237A JP4651826B2 (en) | 2001-01-31 | 2001-01-31 | Reflective display device and manufacturing method thereof |
US10/059,183 US6937302B2 (en) | 2001-01-31 | 2002-01-31 | Liquid crystal display device with particular smoothed insulating layer and method of fabricating the same |
US11/178,464 US20050243250A1 (en) | 2001-01-31 | 2005-07-12 | Liquid crystal display device and method of fabricating the same |
US12/076,475 US20080198315A1 (en) | 2001-01-31 | 2008-03-19 | Liquid crystal display device and method of fabricating the same |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/178,464 Division US20050243250A1 (en) | 2001-01-31 | 2005-07-12 | Liquid crystal display device and method of fabricating the same |
Publications (1)
Publication Number | Publication Date |
---|---|
US20080198315A1 true US20080198315A1 (en) | 2008-08-21 |
Family
ID=18889403
Family Applications (8)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/059,183 Expired - Lifetime US6937302B2 (en) | 2001-01-31 | 2002-01-31 | Liquid crystal display device with particular smoothed insulating layer and method of fabricating the same |
US11/178,464 Abandoned US20050243250A1 (en) | 2001-01-31 | 2005-07-12 | Liquid crystal display device and method of fabricating the same |
US11/178,463 Expired - Lifetime US7522254B2 (en) | 2001-01-31 | 2005-07-12 | Liquid crystal display device and method of fabricating the same |
US11/867,847 Expired - Fee Related US7751022B2 (en) | 2001-01-31 | 2007-10-05 | Liquid crystal display device and method of fabricating the same |
US12/076,475 Abandoned US20080198315A1 (en) | 2001-01-31 | 2008-03-19 | Liquid crystal display device and method of fabricating the same |
US12/076,476 Abandoned US20090079918A1 (en) | 2001-01-31 | 2008-03-19 | Liquid crystal display device and method of fabricating the same |
US12/098,576 Abandoned US20080192188A1 (en) | 2001-01-31 | 2008-04-07 | Liquid crystal display device and method of fabricating the same |
US13/205,204 Expired - Lifetime US8373830B2 (en) | 2001-01-31 | 2011-08-08 | Liquid crystal display device |
Family Applications Before (4)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/059,183 Expired - Lifetime US6937302B2 (en) | 2001-01-31 | 2002-01-31 | Liquid crystal display device with particular smoothed insulating layer and method of fabricating the same |
US11/178,464 Abandoned US20050243250A1 (en) | 2001-01-31 | 2005-07-12 | Liquid crystal display device and method of fabricating the same |
US11/178,463 Expired - Lifetime US7522254B2 (en) | 2001-01-31 | 2005-07-12 | Liquid crystal display device and method of fabricating the same |
US11/867,847 Expired - Fee Related US7751022B2 (en) | 2001-01-31 | 2007-10-05 | Liquid crystal display device and method of fabricating the same |
Family Applications After (3)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/076,476 Abandoned US20090079918A1 (en) | 2001-01-31 | 2008-03-19 | Liquid crystal display device and method of fabricating the same |
US12/098,576 Abandoned US20080192188A1 (en) | 2001-01-31 | 2008-04-07 | Liquid crystal display device and method of fabricating the same |
US13/205,204 Expired - Lifetime US8373830B2 (en) | 2001-01-31 | 2011-08-08 | Liquid crystal display device |
Country Status (4)
Country | Link |
---|---|
US (8) | US6937302B2 (en) |
JP (1) | JP4651826B2 (en) |
KR (1) | KR100746860B1 (en) |
TW (1) | TWI269102B (en) |
Families Citing this family (23)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR100922785B1 (en) * | 2002-08-16 | 2009-10-21 | 엘지디스플레이 주식회사 | Manufacturing for Reflective Liquid Crystal Device display |
KR100957587B1 (en) * | 2002-08-20 | 2010-05-13 | 삼성전자주식회사 | Liquid crystal display device and method for fabricating thereof |
KR100881594B1 (en) * | 2002-08-21 | 2009-02-03 | 엘지디스플레이 주식회사 | In-Plane Switching mode Liquid crystal display device and method for fabricating the same |
TW594230B (en) * | 2002-11-12 | 2004-06-21 | Prime View Int Co Ltd | Reflective plate of reflective-type liquid crystal display and method for producing the same |
KR20050104337A (en) * | 2002-12-14 | 2005-11-02 | 코닌클리즈케 필립스 일렉트로닉스 엔.브이. | Manufacture of shaped structures in lcd cells, and masks therefor |
KR20040062074A (en) | 2002-12-31 | 2004-07-07 | 엘지전자 주식회사 | Structure for fixing fpcb of swing arm assembly in optical recorder |
KR100943258B1 (en) * | 2003-04-15 | 2010-02-18 | 삼성전자주식회사 | Liquid crystal display apparatus and method of fabricating the same |
KR100527187B1 (en) * | 2003-05-01 | 2005-11-08 | 삼성에스디아이 주식회사 | high efficiency OLED and Method for fabricating the same |
TW200531284A (en) | 2003-07-29 | 2005-09-16 | Samsung Electronics Co Ltd | Thin film array panel and manufacturing method thereof |
US7190000B2 (en) * | 2003-08-11 | 2007-03-13 | Samsung Electronics Co., Ltd. | Thin film transistor array panel and manufacturing method thereof |
US7518675B2 (en) * | 2003-09-22 | 2009-04-14 | Tpo Hong Kong Holding Limited | Method of manufacturing liquid crystal display device |
KR100552975B1 (en) * | 2003-11-22 | 2006-02-15 | 삼성에스디아이 주식회사 | active matrix OLED and fabrication method of the same |
KR100990278B1 (en) | 2003-12-18 | 2010-10-26 | 엘지디스플레이 주식회사 | Method of fabricating trans-reflective liquid crystal display device |
JP2005234091A (en) * | 2004-02-18 | 2005-09-02 | Hitachi Displays Ltd | Display device |
US8040444B2 (en) * | 2005-06-03 | 2011-10-18 | Samsung Electronics Co., Ltd. | Display device, method of manufacturing the same and mask for manufacturing the same |
KR101141534B1 (en) * | 2005-06-29 | 2012-05-04 | 엘지디스플레이 주식회사 | Liquid crystal display device and method of fabricating thereof |
KR100629359B1 (en) * | 2005-08-09 | 2006-10-02 | 삼성전자주식회사 | Methods of fabricating a semiconductor device using a photo-sensitive polyimide layer and semiconductor devices fabricated thereby |
JP4835705B2 (en) * | 2009-02-27 | 2011-12-14 | ソニー株式会社 | Method for forming reflective electrode, driving substrate and display device |
JP2012173314A (en) * | 2011-02-17 | 2012-09-10 | Seiko Epson Corp | Wavelength variable interference filter, optical module and electronic apparatus |
KR101382776B1 (en) * | 2012-08-21 | 2014-04-08 | 하이디스 테크놀로지 주식회사 | Liquid crystal display and manufacturing method thereof |
CN104896382B (en) * | 2015-06-18 | 2017-07-21 | 深圳市华星光电技术有限公司 | Backlight module and the liquid crystal display device comprising it |
US9880415B2 (en) * | 2016-01-11 | 2018-01-30 | Giantplus Technology Co., Ltd. | Liquid crystal display module |
US20220037449A1 (en) * | 2018-09-21 | 2022-02-03 | Sharp Kabushiki Kaisha | Display device |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5500750A (en) * | 1993-03-24 | 1996-03-19 | Sharp Kabushiki Kaisha | Manufacturing method of reflection type liquid crystal display devices having light shield elements and reflective electrodes formed of same material |
US5668379A (en) * | 1994-07-27 | 1997-09-16 | Hitachi, Ltd. | Active matrix crystal display apparatus using thin film transistor |
US6400425B1 (en) * | 1999-07-05 | 2002-06-04 | Lg. Philips Lcd Co., Ltd. | TFT-LCD array substrate for testing the short/open-circuit of electric line and a method for fabricating the same |
US6690434B1 (en) * | 1999-03-15 | 2004-02-10 | Semiconductor Energy Laboratory Co., Ltd. | Active matrix liquid crystal display device |
US6747718B2 (en) * | 2000-01-21 | 2004-06-08 | Nec Corporation | Reflection-type liquid crystal display and method for manufacturing the same |
Family Cites Families (20)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE69321523T2 (en) * | 1992-06-26 | 1999-05-06 | Sharp Kk | Reflective liquid crystal display device |
JPH06160833A (en) | 1992-11-20 | 1994-06-07 | Hitachi Ltd | Production of liquid crystal display device |
TW409194B (en) * | 1995-11-28 | 2000-10-21 | Sharp Kk | Active matrix substrate and liquid crystal display apparatus and method for producing the same |
US6175399B1 (en) * | 1997-02-10 | 2001-01-16 | Sharp Kabushiki Kaisha | Reflective type liquid crystal display device having a diffusion layer of phase separated liquid crystal and polymer |
JPH10307305A (en) | 1997-03-07 | 1998-11-17 | Toshiba Corp | Array substrate, liquid crystal display device and production of those |
KR19990001427A (en) * | 1997-06-14 | 1999-01-15 | 구자홍 | Reflective plate of reflective liquid crystal display device and manufacturing method thereof |
JP3305235B2 (en) | 1997-07-01 | 2002-07-22 | 松下電器産業株式会社 | Active element array substrate |
US6310675B1 (en) * | 1997-12-22 | 2001-10-30 | Zvi Yaniv | Liquid crystal display |
JP3372882B2 (en) | 1998-01-30 | 2003-02-04 | シャープ株式会社 | Method for manufacturing substrate in reflective liquid crystal display device |
JP3931936B2 (en) * | 1998-05-11 | 2007-06-20 | セイコーエプソン株式会社 | Microlens array substrate, method for manufacturing the same, and display device |
JP2000017194A (en) | 1998-06-30 | 2000-01-18 | Toyo Alum Kk | Conductive powder and coating, coating film, resin composition and adhesive using the same |
JP3394926B2 (en) * | 1998-09-28 | 2003-04-07 | シャープ株式会社 | Manufacturing method of liquid crystal display device |
JP3768367B2 (en) * | 1998-10-14 | 2006-04-19 | シャープ株式会社 | Liquid crystal display |
JP2000122094A (en) | 1998-10-20 | 2000-04-28 | Sharp Corp | Reflection type liquid crystal display device |
KR20000031459A (en) * | 1998-11-06 | 2000-06-05 | 윤종용 | Reflection type lcd and fabrication method thereof |
JP2000250027A (en) * | 1999-03-02 | 2000-09-14 | Nec Corp | Reflection type liquid crystal display device and its production |
US6291146B1 (en) * | 1999-04-09 | 2001-09-18 | Industrial Technology Research Institute | Method for reforming a reflection-type light diffuser |
JP2001183659A (en) * | 1999-12-22 | 2001-07-06 | Matsushita Electric Ind Co Ltd | Reflection type liquid crystal display device and image display device using the same |
JP2001194662A (en) * | 2000-01-14 | 2001-07-19 | Nec Corp | Reflection type liquid crystal display device and its manufacturing method |
JP2002156651A (en) * | 2000-11-16 | 2002-05-31 | Nec Corp | Method for forming pattern, and method for manufacturing reflection type liquid crystal display device by using the same |
-
2001
- 2001-01-31 JP JP2001024237A patent/JP4651826B2/en not_active Expired - Lifetime
-
2002
- 2002-01-31 US US10/059,183 patent/US6937302B2/en not_active Expired - Lifetime
- 2002-01-31 TW TW091101723A patent/TWI269102B/en not_active IP Right Cessation
- 2002-01-31 KR KR1020020005753A patent/KR100746860B1/en not_active IP Right Cessation
-
2005
- 2005-07-12 US US11/178,464 patent/US20050243250A1/en not_active Abandoned
- 2005-07-12 US US11/178,463 patent/US7522254B2/en not_active Expired - Lifetime
-
2007
- 2007-10-05 US US11/867,847 patent/US7751022B2/en not_active Expired - Fee Related
-
2008
- 2008-03-19 US US12/076,475 patent/US20080198315A1/en not_active Abandoned
- 2008-03-19 US US12/076,476 patent/US20090079918A1/en not_active Abandoned
- 2008-04-07 US US12/098,576 patent/US20080192188A1/en not_active Abandoned
-
2011
- 2011-08-08 US US13/205,204 patent/US8373830B2/en not_active Expired - Lifetime
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5500750A (en) * | 1993-03-24 | 1996-03-19 | Sharp Kabushiki Kaisha | Manufacturing method of reflection type liquid crystal display devices having light shield elements and reflective electrodes formed of same material |
US5668379A (en) * | 1994-07-27 | 1997-09-16 | Hitachi, Ltd. | Active matrix crystal display apparatus using thin film transistor |
US5760854A (en) * | 1994-07-27 | 1998-06-02 | Hitachi, Ltd. | Liquid crystal display apparatus |
US6690434B1 (en) * | 1999-03-15 | 2004-02-10 | Semiconductor Energy Laboratory Co., Ltd. | Active matrix liquid crystal display device |
US6400425B1 (en) * | 1999-07-05 | 2002-06-04 | Lg. Philips Lcd Co., Ltd. | TFT-LCD array substrate for testing the short/open-circuit of electric line and a method for fabricating the same |
US6747718B2 (en) * | 2000-01-21 | 2004-06-08 | Nec Corporation | Reflection-type liquid crystal display and method for manufacturing the same |
Also Published As
Publication number | Publication date |
---|---|
US20020101556A1 (en) | 2002-08-01 |
JP2002229060A (en) | 2002-08-14 |
US20080192188A1 (en) | 2008-08-14 |
US20090079918A1 (en) | 2009-03-26 |
US6937302B2 (en) | 2005-08-30 |
US7522254B2 (en) | 2009-04-21 |
US20080286890A1 (en) | 2008-11-20 |
JP4651826B2 (en) | 2011-03-16 |
KR20020064213A (en) | 2002-08-07 |
US20050243249A1 (en) | 2005-11-03 |
US20050243250A1 (en) | 2005-11-03 |
KR100746860B1 (en) | 2007-08-07 |
TWI269102B (en) | 2006-12-21 |
US7751022B2 (en) | 2010-07-06 |
US20110285946A1 (en) | 2011-11-24 |
US8373830B2 (en) | 2013-02-12 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7522254B2 (en) | Liquid crystal display device and method of fabricating the same | |
US7580088B2 (en) | Contact for semiconductor and display devices | |
US8068188B2 (en) | Thin film transistor array panel and manufacturing method thereof | |
KR100515176B1 (en) | Liquid crystal display panel having reflection electrodes improved in smooth surface morphology and process for fabrication thereof | |
TW574555B (en) | Active-matrix addressed reflective LCD and method of fabricating the same | |
US20050218404A1 (en) | Reflective liquid crystal display device | |
US7317208B2 (en) | Semiconductor device with contact structure and manufacturing method thereof | |
JP2002328396A (en) | Liquid crystal display device and its manufacturing method | |
US7439088B2 (en) | Liquid crystal display device and fabricating method thereof | |
JP2002350897A (en) | Method for manufacturing matrix substrate for liquid crystal | |
JP3510129B2 (en) | Manufacturing method of liquid crystal display element | |
KR100471765B1 (en) | Thin film transistor substrate with single film gate line and manufacturing method | |
KR100483525B1 (en) | Manufacturing method of liquid crystal display device using organic insulating film | |
KR100560639B1 (en) | The structure of thin film transistor in reflection type LCD and method of forming it | |
JPH05134271A (en) | Liquid crystal display device | |
JP2009300636A (en) | Liquid crystal display panel and method of manufacturing the same |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: NEC LCD TECHNOLOGIES, LTD., JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:NEC CORPORATION;REEL/FRAME:020716/0536 Effective date: 20030401 Owner name: NEC CORPORATION, JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KIKKAWA, HIRONORI;SAKAMOTO, MICHIAKI;YAMAGUCHI, YUICHI;AND OTHERS;REEL/FRAME:020716/0543 Effective date: 20020125 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |