KR20060081586A - Thin film transistor array panel - Google Patents

Abstract

The present invention relates to a thin film transistor array panel, wherein the thin film transistor array panel is formed on a substrate, a gate line formed on the substrate, a gate insulating film formed on the gate line, a data line formed on the gate insulating film, and a data line. An organic insulating film having an uneven pattern, a transparent electrode formed on the organic insulating film and defining a transmissive region, and a reflective electrode formed on the transparent electrode and defining a reflective region, are included. In this case, the upper region of the data line has a first region adjacent to the transmission region and a second region adjacent to the reflective region, and the reflective electrode is formed in the second region but not formed in the first region.

Liquid crystal display, transflective, reflective electrode, transparent electrode, uneven pattern, lifting phenomenon

Description

Thin Film Transistor Display Panels {THIN FILM TRANSISTOR ARRAY PANEL}

1 is a layout view of a thin film transistor array panel according to an exemplary embodiment of the present invention.

2 and 3 are cross-sectional views of the thin film transistor array panel illustrated in FIG. 1 taken along lines II-II 'and III-III', respectively.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to thin film transistor array panels, and more particularly to transflective thin film transistor array panels.

In general, a liquid crystal display device includes a liquid crystal layer positioned between a field generating electrode and a pair of display panels provided with a polarizing plate. The field generating electrode generates an electric field in the liquid crystal layer and the arrangement of the liquid crystal molecules changes as the intensity of the electric field changes. For example, in the state where an electric field is applied, the liquid crystal molecules of the liquid crystal layer change its arrangement to change the polarization of light passing through the liquid crystal layer. The polarizer displays a desired image by appropriately blocking or transmitting polarized light to create bright and dark areas.

Since the liquid crystal display is a light-receiving display device that does not emit light by itself, light from a lamp of a separately provided backlight unit passes through the liquid crystal layer, or light from external sources such as natural light passes through the liquid crystal layer once again. Reflects and passes the liquid crystal layer again. The former case is called a transmissive liquid crystal display device, and the latter case is called a reflective liquid crystal display device. The latter case is mainly used for small and medium size display devices. In addition, a semi-transmissive or reflective-transmissive liquid crystal display device using either a backlight device or an external light is developed according to the environment, and is mainly applied to a small and medium display device.

In the case of the transflective liquid crystal display, each pixel includes a transmissive region using a backlight device and a reflective region using external light. The transmissive region includes a transparent electrode, and the reflective region has a reflective electrode. An uneven pattern is formed in the organic insulating layer formed under the reflective electrode, thereby inducing the uneven pattern to the reflective electrode to increase the reflection efficiency of the reflective electrode.

The reflective electrode may be formed of a "W" shaped structure surrounding the entire edge of the transparent electrode, or may be formed of a "U" shaped structure surrounding both edges of the transparent electrode adjacent to a neighboring data line, or may be adjacent to one data line. It is formed in the "L" shape surrounding one edge of a transparent electrode. By arranging the reflective electrodes around the data lines in this way, the reflecting region is widened to increase the reflectance. However, due to the step between the reflective and transparent regions, a so-called lifting phenomenon occurs in which the reflective electrode around the data line is separated from the transparent electrode, which is a lower layer thereof, thereby affecting the image quality.

Accordingly, an aspect of the present invention is to provide a thin film transistor array panel capable of minimizing a lifting phenomenon.

According to one or more exemplary embodiments, a thin film transistor array panel having a transmissive region and a reflective region includes a substrate, a gate line formed on the substrate, a gate insulating film formed on the gate line, and the gate. A data line formed on the insulating film, an organic insulating film formed on the data line and having an uneven pattern, a transparent electrode formed on the organic insulating film and defining the transmission area, and formed on the transparent electrode, A reflective electrode, wherein the upper region of the data line has a first region adjacent to the transmission region and a second region adjacent to the reflective region, and the reflective electrode is formed in the second region, but the first region Not formed.

The light blocking member may further include a light blocking member formed under the data line to block external light from a lower portion of the substrate.

The reflective electrode may overlap the data line of the second region.

The reflective electrode may overlap the gate line.

The organic insulating layer may be removed in the transmission region.

The organic insulating layer may be removed in the first region.

DETAILED DESCRIPTION Embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. Like parts are designated by like reference numerals throughout the specification. When a part of a layer, film, region, plate, etc. is said to be "on" another part, this includes not only the other part being "right over" but also another part in the middle. On the contrary, when a part is "just above" another part, there is no other part in the middle.

A thin film transistor array panel according to an exemplary embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 is a layout view of a thin film transistor array panel according to an exemplary embodiment of the present invention, and FIGS. 2 and 3 are each cut along the II-II 'and III-III' lines of the liquid crystal display shown in FIG. It is a cross section.

In the thin film transistor array panel 100 according to the present exemplary embodiment, as illustrated in FIGS. 1 to 3, a plurality of gate lines 121 and a plurality of light blocking layers are formed on an insulating substrate 110 made of transparent glass or the like. The member 126 and the plurality of storage electrode lines 131 are formed.

The gate lines 121 mainly extend in the horizontal direction, are separated from each other, and transmit gate signals. Each gate line 121 has a plurality of protrusions constituting the gate electrode 124, and an extension 129 at one end of the gate line 121 has a large area for connection with an external circuit.                     

The light blocking members 126 extend mainly in the longitudinal direction and are separated from each other, and block light from a lamp of a backlight device (not shown).

The storage electrode line 131 mainly extends in the horizontal direction and includes a plurality of protrusions constituting the storage electrode 133. The storage electrode line 131 receives a predetermined voltage such as a common voltage applied to the common electrode 270 of the common electrode display panel 200.

The gate line 121, the light blocking member 126, and the storage electrode line 131 may be formed of aluminum-based metal such as aluminum and aluminum alloy, silver-based metal such as silver and silver alloy, copper-based metal such as copper and copper alloy, molybdenum and Molybdenum-based metals such as molybdenum alloys, chromium, titanium, tantalum and the like is preferably made. The gate line 121, the light blocking member 126, and the storage electrode line 131 may include two layers having different physical properties, that is, a lower layer (not shown) and an upper layer (not shown) thereon. . The upper layer is made of a metal having a low resistivity, such as aluminum (Al) or an aluminum alloy, so as to reduce signal delay or voltage drop between the gate line 121 and the storage electrode line 131. In contrast, the lower layer is made of a material having excellent contact properties with other materials, particularly indium tin oxide (ITO) and indium zinc oxide (IZO), such as molybdenum (Mo), molybdenum alloy, chromium (Cr), and the like. An example of the combination of the lower layer and the upper layer is chromium / aluminum-neodymium (Nd) alloy.

The gate line 121, the light blocking member 126, and the storage electrode line 131 may have a single layer structure or may include three or more layers.                     

In addition, side surfaces of the gate line 121, the light blocking member 126, and the storage electrode line 131 are inclined with respect to the surface of the substrate 110, and the inclination angle thereof is about 20-80 °.

A gate insulating layer 140 made of silicon nitride (SiNx) is formed on the gate line 121, the light blocking member 126, and the storage electrode line 131.

On the gate insulating layer 140, a plurality of linear semiconductors 151 made of hydrogenated amorphous silicon (amorphous silicon is abbreviated a-Si), polycrystalline silicon, or the like are formed. The linear semiconductor 151 extends mainly in the longitudinal direction, from which a plurality of extensions 154 extend toward the gate electrode 124, from which a plurality of extensions 157 extend. In addition, the linear semiconductor 151 increases in width near the point where the linear semiconductor 151 meets the gate line 121 and the storage electrode line 131 to cover a large area of the gate line 121 and the storage electrode line 131.

A plurality of linear and island ohmic contacts 161 and 165 made of a material such as n + hydrogenated amorphous silicon doped with silicide or n-type impurities at a high concentration are formed on the semiconductor 151. have. The linear contact member 161 has a plurality of protrusions 163, and the protrusions 163 and the island contact members 165 are paired and positioned on the protrusions 154 of the semiconductor 151.

Side surfaces of the semiconductor 151 and the ohmic contacts 161 and 165 are also inclined with respect to the surface of the substrate 110, and the inclination angle is 30-80 °.

A plurality of data lines 171 and a plurality of drain electrodes 175 separated therefrom are formed on the ohmic contacts 161 and 165 and the gate insulating layer 140.

The data line 171 mainly extends in the vertical direction and crosses the gate line 121 and the storage electrode line 131 and transmits a data voltage. The data line 171 is widened at both ends of the light blocking member 126 to block light that is not blocked by the light blocking member 126. The data line 171 includes an extension 179 at one end having a large area for connecting to another layer or an external device.

Each drain electrode 175 includes an extension 177 that overlaps one storage electrode 133. Each vertical portion of the data line 171 includes a plurality of protrusions, and the vertical portion including the protrusions forms a source electrode 173 partially surrounding one end of the drain electrode 175. The gate electrode 124, the source electrode 173, and the drain electrode 175 form a thin film transistor (TFT) together with the protrusion 154 of the semiconductor 151, and the channel of the thin film transistor is a source. A protrusion 154 is formed between the electrode 173 and the drain electrode 175.

The data line 171 and the drain electrode 175 are preferably made of a refractory metal such as chromium or molybdenum-based metal, tantalum, and titanium, and include a lower layer such as molybdenum (Mo), molybdenum alloy, and chromium (Cr). And an upper layer (not shown) that is an aluminum-based metal disposed thereon.

Similarly to the gate line 121, the light blocking member 126, and the storage electrode line 131, the data line 171 and the drain electrode 175 are inclined at an angle of about 30-80 °, respectively.                     

The ohmic contacts 161 and 165 exist only between the semiconductor 151 below and the data line 171 and the drain electrode 175 above and serve to lower the contact resistance. The linear semiconductor 151 has a portion exposed between the source electrode 173 and the drain electrode 175 and not covered by the data line 171 and the drain electrode 175.

A passivation layer 180 made of silicon nitride or silicon oxide, which is an inorganic material, is formed on the data line 171, the drain electrode 175, and the exposed semiconductor 151, and the upper portion of the passivation layer 180. An organic insulating layer 187 formed of an organic material having excellent planarization characteristics and photosensitivity is formed therein. At this time, the surface of the organic insulating layer 187 has a concave-convex pattern, inducing a concave-convex pattern on the reflective electrode 192 formed on the organic insulating film 187 to maximize the reflection efficiency of the reflective electrode 192. The organic insulating layer 187 is removed and only the passivation layer 180 remains on the pad part where the extension parts 129 and 179 of the gate line 121 and the data line 171 are formed.

In the passivation layer 180, a contact hole 182 is formed to expose the extension 179 of the data line 171. The extension 129 of the gate line 121 together with the gate insulating layer 140 is formed. The contact hole 181 which exposes is formed. In addition, the protective layer 180 and the organic insulating layer 187 are formed with contact holes 185 exposing the extension 177 of the drain electrode 175. The contact holes 181, 182, and 185 may be made in various shapes such as polygons or circles, and the sidewalls are inclined or stepped at an angle of 30-85 °.                     

A plurality of pixel electrodes are formed on the organic insulating layer 187.

The pixel electrode includes a transparent electrode 190 and a reflective electrode 192 formed on the transparent electrode 190. The transparent electrode 190 may be made of ITO or IZO, which is a transparent conductive material, and the reflective electrode 192 may be made of aluminum or an aluminum alloy, silver, or a silver alloy having opacity and reflectivity. The pixel electrode may further include a contact auxiliary layer (not shown) made of molybdenum or molybdenum alloy, chromium, titanium, or tantalum. The contact auxiliary layer secures contact characteristics between the transparent electrode 190 and the reflective electrode 192 and prevents the transparent electrode 190 from oxidizing the reflective electrode 192.

One pixel is largely divided into a transmission area TA and a reflection area RA. The transmission area TA is an area where the reflection electrode 192 is removed, and the reflection area RA is a reflection electrode 192. This area exists. The organic insulating film 187 is removed from the transmission area TA, and the cell spacing in the transmission area TA is approximately twice the cell spacing in the reflection area RA. Therefore, the influence of the optical path difference through which the light passes through the liquid crystal layer 3 in the reflection area RA and the transmission area TA can be compensated for. The organic insulating layer 187 may be removed from the upper portion of the data line 171 at both edges of the transmission area TA, so that only the passivation layer 180 may remain.

The transmission area TA and the reflection area are divided into one pixel. That is, the transmission area TA is formed between the front gate line 121 and the adjacent data line 171 adjacent thereto, and the reflection area RA is formed between the gate line 121 and the transmission area TA under the transmission area TA. It is formed between neighboring data lines 171 adjacent thereto. That is, the reflective electrode 192 is not formed in the upper region of the data line 171 adjacent to the transparent electrode 190. Therefore, the lifting phenomenon of the reflective electrode 192 caused by being formed in the narrow area above the data line 171 can be prevented at the source. Since the reflective electrode 192 formed on the data line 171 in the reflective region RA is formed in a wide range, a lifting phenomenon does not occur.

The pixel electrode is physically and electrically connected to the extension 177 of the drain electrode 175 through the contact hole 185 to receive a data voltage from the drain electrode 175. The pixel electrode to which the data voltage is applied rearranges the liquid crystal molecules of the liquid crystal layer 3 between the two by generating an electric field together with the common electrode 270.

In addition, the pixel electrode and the common electrode 270 form a capacitor (hereinafter referred to as a "liquid crystal capacitor") to maintain the applied voltage even after the thin film transistor is turned off. There is another capacitor connected in parallel with it, which is called a storage capacitor. The storage capacitor is made by overlapping the extension 177 of the drain electrode 175 and the storage electrode 133. The storage capacitor may be formed by overlapping the pixel electrode and the neighboring gate line 121, and the storage electrode line 131 may be omitted.

The transparent electrode 190 overlaps the light blocking member 126 to increase the aperture ratio. Although the drawing illustrates that the transparent electrode 190 does not overlap the gate line 121, the transparent electrode 190 may overlap to further increase the aperture ratio. In addition, the reflective region RA may be extended by forming the reflective electrode 192 on the upper portion of the semiconductor 154 channel portion and the sustain electrode 133, thereby increasing the reflectance.

A transparent conductive polymer or the like may be used as the material of the pixel electrode, and in the case of a reflective liquid crystal display, an opaque reflective metal may be used.

On the passivation layer 180 of the pad part, a plurality of contact auxiliary members connected to the expansion part 129 of the gate line 121 and the expansion part 179 of the data line 171 through the contact holes 181 and 182, respectively. contact assistants 81 and 82 are formed. The contact auxiliary members 81 and 82 complement the adhesion between the extension portions 129 and 179 of the gate line 121 and the data line 171 and the external device, and do not necessarily serve to protect them. Whether to apply is optional. They may also be formed of the same layer as the transparent electrode 190 or the reflective electrode 192.

According to the present invention, the lifting phenomenon of the reflective electrode can be prevented by not forming the reflective electrode in the upper region of the data line adjacent to the transparent electrode. In addition, by forming a reflective electrode on the semiconductor channel portion and the portion where the sustain electrode is formed, the reflective region can be expanded, thereby increasing the reflectance.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

Claims (6)

A thin film transistor array panel having a transmission region and a reflection region, Board, A gate line formed on the substrate, A gate insulating film formed on the gate line, A data line formed on the gate insulating film, An organic insulating layer formed on the data line and having an uneven pattern; A transparent electrode formed on the organic insulating film and defining the transmission region, and A reflective electrode formed on the transparent electrode and defining the reflective region Including; An upper region of the data line has a first region adjacent to the transmission region and a second region adjacent to the reflective region, and the reflective electrode is formed in the second region but is not formed in the first region. Thin film transistor array panel. In claim 1, And a light blocking member formed under the data line and blocking external light from a lower portion of the substrate. In claim 1, The reflective electrode overlaps the data line of the second region. In claim 1, The reflective electrode overlaps the gate line. In claim 1, And the organic insulating layer is removed from the transmission region. In claim 5, The organic insulating layer is removed in the first region.

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