KR20070039275A - Thin film transistor array panel - Google Patents

Abstract

The thin film transistor array panel according to the present invention includes a substrate, a gate line formed on the substrate, a light blocking member formed on the substrate and separated from the gate line, a gate insulating film formed on the gate line, and formed on the gate insulating film and overlapping the light blocking member. And a data line formed on the semiconductor and a semiconductor, a data line including a source electrode, a drain electrode formed on the semiconductor and facing the source electrode, a passivation layer and a passivation layer formed on the data line and the drain electrode. And a pixel electrode connected to each other, and a connection member formed on the passivation layer and connecting the light blocking member and the data line.

Leakage Current, Semiconductor, Optical

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.

FIG. 2 is a cross-sectional view of the thin film transistor array panel of FIG. 1 taken along the line II-II.

3 is a cross-sectional view of the thin film transistor array panel of FIG. 1 taken along line III-III.

4 is a layout view at an intermediate stage of a method of manufacturing a thin film transistor array panel according to another exemplary embodiment of the present invention.

5 is a cross-sectional view of the thin film transistor array panel of FIG. 4 taken along the line V-V.

6 is a cross-sectional view of the thin film transistor array panel of FIG. 4 taken along the line VI-VI.

7 and 8 are cross-sectional views at the next stage of FIGS. 5 and 6.

9 and 10 are cross-sectional views of the next steps of FIGS. 7 and 8, and FIG. 11 is a layout view of the thin film transistor array panel of the next steps of FIGS. 9 and 10.

FIG. 12 is a cross-sectional view of the thin film transistor array panel of FIG. 11 taken along the line XII-XII.

FIG. 13 is a cross-sectional view of the thin film transistor array panel of FIG. 11 taken along the line XIII-XIII.

FIG. 14 is a layout view of a thin film transistor array panel in the next step of FIG. 11.

FIG. 15 is a cross-sectional view of the thin film transistor array panel of FIG. 14 taken along the line XV-XV.

FIG. 16 is a cross-sectional view of the thin film transistor array panel of FIG. 14 taken along the line XVI-XVI.

* Description of Drawing Symbols *

81, 82: contact auxiliary member 86: connecting member

110: substrate 121: gate line

122: light blocking member 140: gate insulating film

151 and 154: semiconductors 161 and 165: ohmic contact members

171: data line 173: source electrode

175: drain electrode 180: protective film

181, 182, 186: contact hole

191: pixel electrode

The present invention relates to a thin film transistor array panel.

Liquid crystal display is one of the most widely used flat panel displays. It consists of two substrates on which electrodes are formed and a liquid crystal layer interposed between them. The display device is applied to rearrange the liquid crystal molecules of the liquid crystal layer to control the amount of light transmitted.

Among the liquid crystal display devices, which are currently mainly used are structures in which electric field generating electrodes are provided on two display panels, respectively. Among these, a plurality of pixel electrodes are arranged in a matrix form on one display panel (hereinafter referred to as a 'thin film transistor display panel'), and one common electrode is used on another display panel (hereinafter, referred to as a 'common electrode display panel'). The shape of the structure covering the front is mainstream. The display of an image in such a liquid crystal display is performed by applying a separate voltage to each pixel electrode. To this end, a thin film transistor, which is a three-terminal element for switching the voltage applied to the pixel electrode, is connected to each pixel electrode, and a gate line for transmitting a signal for controlling the thin film transistor and a voltage to be applied to the pixel electrode are selected. A data line to transfer is formed on the display panel.

The thin film transistor serves as a switching element that transfers or blocks an image signal transmitted through a data line to a pixel electrode according to a scan signal transmitted through a gate line. Such a thin film transistor also serves as a switching element for individually controlling each light emitting element in an active organic light emitting diode (AM-OLED) which is a self-luminous element.

The thin film transistor array panel includes a plurality of thin films including a metal layer including a gate line and a data line, a semiconductor, and an insulating layer, and each thin film is patterned using a separate mask.

However, as one more mask is added, the process time and cost are remarkably increased since the photoresist coating, exposure, development and cleaning processes must be repeated. Therefore, it is necessary to reduce the number of possible masks.

Accordingly, a method of etching the data metal film and the semiconductor with one mask has been proposed.

However, when the data metal film and the semiconductor are etched with one mask, the semiconductor remains on the entire lower surface of the data metal film. In this case, when the semiconductor is exposed to a light source such as a backlight, a light leakage current is generated, which may deteriorate the characteristics of the thin film transistor array panel and may be visually recognized as an afterimage from the outside.

Accordingly, an object of the present invention is to provide a thin film transistor array panel in which the generation of light leakage current is reduced and no afterimage occurs.

According to the present invention for achieving the above object, a thin film transistor array panel includes a substrate, a gate line formed on the substrate, a light blocking member formed on the substrate and separated from the gate line, a gate insulating film formed on the gate line, and a gate insulating film. A semiconductor formed on the semiconductor layer and overlapping the light blocking member, a data line formed on the semiconductor, a data line including a source electrode, a drain electrode formed on the semiconductor and facing the source electrode, a protective film formed on the data line and the drain electrode, and a protective film And a pixel electrode which is formed and electrically connected to the drain electrode, and a connection member which is formed on the passivation layer and connects the light blocking member and the data line.

It may further include an ohmic contact formed between the semiconductor and the data line.

The semiconductor may include a first portion having a planar shape substantially the same as the data line and the drain electrode, and a second portion not covered with the data line and the drain electrode and positioned between the source electrode and the drain electrode.

The ohmic contact may have the same planar shape as the data line and the drain electrode.

The data line and the semiconductor have an opening that exposes the light blocking member, the protective film has a contact hole that exposes the opening, and the connection member can connect the data line and the light blocking member through the contact hole and the opening.

The contact hole exposes the surface above the data line around the opening, and the connecting member may contact the surface of the data line exposed through the contact hole together with the side surface of the data line exposed through the opening.

DETAILED DESCRIPTION Hereinafter, exemplary 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 portion of a layer, film, region, plate, etc. is said to be "on top" of another part, this includes not only when the other part is "right over" but also when there is another part in the middle. On the contrary, when a part is "just above" another part, there is no other part in the middle.

Next, a thin film transistor array panel according to an exemplary embodiment of the present invention will be described in detail with reference to FIGS. 1 to 3.

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 cross-sectional views illustrating the thin film transistor array panel of FIG. 1 taken along lines II-II and III-III, respectively.

A plurality of gate lines 121, a plurality of storage electrode lines 131, and a light blocking member 122 are formed on an insulating substrate 110 made of transparent glass or plastic.

The gate line 121 transmits a gate signal and mainly extends in a horizontal direction. Each gate line 121 includes a plurality of gate electrodes 124 protruding downward and a wide end portion 129 for connection with another layer or an external driving circuit. A gate driving circuit (not shown) for generating a gate signal may be mounted on a flexible printed circuit film (not shown) attached to the substrate 110 or directly mounted on the substrate 110, It may be integrated into the substrate 110. When the gate driving circuit is integrated on the substrate 110, the gate line 121 may extend to be directly connected to the gate driving circuit.

The storage electrode line 131 receives a predetermined voltage, and includes a stem line extending substantially in parallel with the gate line 121 and a plurality of pairs of storage electrodes 133a and 133b separated therefrom. Each of the storage electrode lines 131 is positioned between two adjacent gate lines 121, and the stem line is closer to the lower side of the two gate lines 121. Each of the sustain electrodes 133a and 133b has a fixed end connected to the stem line and a free end opposite thereto. The fixed end of one sustain electrode 133b has a large area, and its free end is divided into two parts, a straight part and a bent part. However, the shape and arrangement of the storage electrode line 131 may be modified in various ways.

The light blocking member 122 is formed apart from the gate line 121 and is elongated in a direction perpendicular to the gate line 121. The light blocking member 122 is repeatedly disposed at predetermined intervals between two adjacent gate lines 121.

The gate line 121, the storage electrode line 131, and the light blocking member 122 may be formed of aluminum-based metal such as aluminum (Al) or aluminum alloy, silver-based metal such as silver (Ag) or silver alloy, copper (Cu), copper alloy, or the like. It may be made of copper-based metals, molybdenum-based metals such as molybdenum (Mo) or molybdenum alloys, chromium (Cr), tantalum (Ta) and titanium (Ti). However, they may have a multi-film structure including two conductive films (not shown) having different physical properties. One of the conductive films is made of a metal having low resistivity, such as aluminum-based metal, silver-based metal, or copper-based metal, so as to reduce signal delay or voltage drop. In contrast, other conductive films are made of other materials, particularly materials having excellent physical, chemical, and electrical contact properties with indium tin oxide (ITO) and indium zinc oxide (IZO), such as molybdenum-based metals, chromium, tantalum, and titanium. Good examples of such a combination include a chromium bottom film, an aluminum (alloy) top film, and an aluminum (alloy) bottom film and a molybdenum (alloy) top film. However, the gate line 121 and the storage electrode line 131 may be made of various other metals or conductors.

Side surfaces of the gate line 121, the storage electrode line 131, and the light blocking member 122 are inclined with respect to the surface of the substrate 110, and the inclination angle is preferably about 30 ° to about 80 °.

A gate insulating layer 140 made of silicon nitride (SiNx) or silicon oxide (SiOx) is formed on the gate line 121, the storage electrode line 131, and the light blocking member 1220.

A plurality of linear semiconductors 151 made of hydrogenated chlorinated amorphous silicon (a-Si) or polycrystalline silicon are formed on the gate insulating layer 140. The linear semiconductor 151 mainly extends in the longitudinal direction and includes a plurality of projections 154 extending toward the gate electrode 124. The linear semiconductor 151 is disposed to overlap the light blocking member 122.

A plurality of linear and island ohmic contacts 161 and 165 are formed on the semiconductor 151. The ohmic contacts 161 and 165 may be made of a material such as n + hydrogenated amorphous silicon in which n-type impurities such as phosphorus (P) are heavily doped, or may be made of silicide. The linear ohmic contact 161 has a plurality of protrusions 163, and the protrusion 163 and the island-type ohmic contact 165 are paired and disposed on the protrusion 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 about 30 ° to about 80 °.

A plurality of data lines 171 and a plurality of drain electrodes 175 are formed on the ohmic contacts 161 and 165.

The data line 171 transmits a data signal and mainly extends in a vertical direction to cross the gate line 121 and overlap the light blocking member 122. Each data line 171 also crosses the storage electrode line 131 and is formed between a set of adjacent storage electrodes 133a and 133b. An opening 171H exposing the light blocking member 122 is formed in the data line 171, the ohmic contact 161, and the semiconductor 151. Each data line 171 includes a plurality of source electrodes 173 extending toward the gate electrode 124 and an end portion 179 having a large area for connection with another layer or an external driving circuit. A data driving circuit (not shown) for generating a data signal is mounted on a flexible printed circuit film (not shown) attached to the substrate 110, directly mounted on the substrate 110, or integrated in the substrate 110. Can be. When the data driving circuit is integrated on the substrate 110, the data line 171 may be extended to be directly connected to the data driving circuit.

The drain electrode 175 is separated from the data line 171 and faces the source electrode 173 with respect to the gate electrode 124. Each drain electrode 175 has one end portion having a large area and the other end portion having a rod shape. The wide end portion overlaps the storage electrode line 131, and the rod-shaped end portion is partially surrounded by the source electrode 173 bent in a C shape.

One gate electrode 124, one source electrode 173, and one drain electrode 175 together with the protrusion 154 of the semiconductor 151 form one thin film transistor (TFT). A channel of the transistor is formed in the protrusion 154 between the source 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 molybdenum, chromium, tantalum, and titanium, or an alloy thereof, and include a refractory metal film (not shown) and a low resistance conductive film. It may have a multilayer structure including (not shown). Examples of the multilayer structure include a double layer of chromium or molybdenum (alloy) lower layer and an aluminum (alloy) upper layer, and a triple layer of molybdenum (alloy) lower layer and aluminum (alloy) interlayer and molybdenum (alloy) upper layer. However, the data line 171 and the drain electrode 175 may be made of various metals or conductors.

The side of the data line 171 and the drain electrode 175 may also be inclined at an inclination angle of about 30 ° to about 80 ° with respect to the surface of the substrate 110.

The ohmic contacts 161 and 165 exist only between the semiconductor 151 below and the data line 171 and the drain electrode 175 thereon, thereby lowering the contact resistance therebetween. The semiconductor 151 has a substantially planar shape with the data line 171, the drain electrode 175, and the ohmic contacts 161 and 165 thereunder. However, the semiconductor 151 may be exposed between the source electrode 173 and the drain electrode 175 and not be covered by the data line 171 and the drain electrode 175.

A passivation layer 180 is formed on the data line 171, the drain electrode 175, and the exposed semiconductor 154. The passivation layer 180 is made of an inorganic insulator such as silicon nitride or silicon oxide, an organic insulator, or a low dielectric insulator. The dielectric constant of the organic insulator and the low dielectric insulator is preferably 4.0 or less. Examples of the low dielectric insulator include a-Si: C: O and a-Si: O formed by plasma enhanced chemical vapor deposition (PECVD). : F, etc. can be mentioned. The passivation layer 180 may be formed by having photosensitivity among the organic insulators, and the surface of the passivation layer 180 may be flat. However, the passivation layer 180 may have a double layer structure of the lower inorganic layer and the upper organic layer so as not to damage the exposed portion of the semiconductor 151 while maintaining excellent insulating properties of the organic layer.

In the passivation layer 180, a plurality of contact holes 182 and 185 exposing the end portion 179 and the drain electrode 175 of the data line 171 are formed, respectively, and the passivation layer 180 and the gate insulating layer are formed. 140, a plurality of contact holes 181 exposing the end portion 129 of the gate line 121, a plurality of contact holes 183 exposing a part of the sustain electrode line 131 near the fixed end of the sustain electrode 133b, A plurality of contact holes 184 exposing the free end of the sustain electrode 133b are formed. In addition, a contact hole 186 exposing the light blocking member 122 is formed in the passivation layer 180 and the gate insulating layer 140 corresponding to the opening 171H of the data line 171. The contact hole 186 is formed to be wider than the opening 171H, and partially exposes a surface on the data line 171 around the opening 171H.

A plurality of pixel electrodes 191, a plurality of overpasses 84, a plurality of contact assistants 81 and 82, and a connecting member 86 are formed on the passivation layer 180. It is. These may be made of a transparent conductive material such as ITO or IZO or a reflective metal such as aluminum, silver or an alloy thereof.

The pixel electrode 191 is physically and electrically connected to the drain electrode 175 through the contact hole 185 and receives a data voltage from the drain electrode 175. The pixel electrode 191 to which the data voltage is applied has a liquid crystal between the two electrodes by generating an electric field together with a common electrode (not shown) of another display panel (not shown) to which a common voltage is applied. The direction of the liquid crystal molecules in the layer (not shown) is determined. The pixel electrode 191 and the common electrode form a capacitor (hereinafter, referred to as a "liquid crystal capacitor") to maintain an applied voltage even after the thin film transistor is turned off.

The pixel electrode 191 overlaps the storage electrode line 131 including the storage electrodes 133a and 133b. A capacitor formed by the pixel electrode 191 and the drain electrode 175 electrically connected to the pixel electrode 191 overlapping the storage electrode line 131 is called a storage capacitor, and the storage capacitor enhances the voltage holding capability of the liquid crystal capacitor.

The contact auxiliary members 81 and 82 are connected to the end portion 129 of the gate line 121 and the end portion 179 of the data line 171 through the contact holes 181 and 182, respectively. The contact auxiliary members 81 and 82 compensate for and protect the adhesion between the end portions 179 and 129 of the data line 171 and the gate line 121 and the external device.

The connecting leg 84 crosses the gate line 121, and the exposed portion of the storage electrode line 131 and the storage electrode 133b through the contact hole 184 positioned on the opposite side with the gate line 121 interposed therebetween. It is connected to the exposed end of the free end. The sustain electrode lines 131 including the sustain electrodes 133a and 133b may be used together with the connecting legs 84 to repair defects in the gate line 121, the data line 171, or the thin film transistor.

The connection member 86 connects the data line 171 and the light blocking member 122 through the contact hole 186. The connecting member 86 contacts the upper surface of the light blocking member 122, and contacts the upper surface of the data line 171 exposed through the sidewall of the opening 176H of the data line 171 and the contact hole 186. Contact.

Next, a method of manufacturing a thin film transistor array panel according to another exemplary embodiment of the present invention will be described with reference to FIGS. 4 through 16.

4 is a layout view at an intermediate stage of a method of manufacturing a thin film transistor array panel according to another exemplary embodiment of the present invention, FIG. 5 is a cross-sectional view of the thin film transistor array panel of FIG. 4 taken along a line VV, and FIG. 4 is a cross-sectional view of the thin film transistor array panel of FIG. 4 taken along the line VI-VI, and FIGS. 7 and 8 are cross-sectional views of the next steps of FIGS. 5 and 6, and FIGS. 9 and 10 are next to FIGS. 7 and 8. FIG. 11 is a layout view of a thin film transistor array panel in the next steps of FIGS. 9 and 10, FIG. 12 is a cross-sectional view of the thin film transistor array panel of FIG. 11 taken along the line XII-XII, and FIG. 13. 11 is a cross-sectional view of the thin film transistor array panel of FIG. 11 taken along the line XIII-XIII, FIG. 14 is a layout view of the thin film transistor array panel in the next step of FIG. 11, and FIG. 15 is a thin film transistor array panel of FIG. FIG. 16 is a cross-sectional view taken along the XV-XV line, and FIG. 16 is a cross-sectional view taken along the XVI-XVI line of the thin film transistor array panel of FIG. 14.

First, as shown in FIGS. 4 to 6, a metal film is formed on an insulating substrate 110 made of transparent glass or plastic. Then, by wet or dry etching, the plurality of gate lines 121 including the gate electrode 124 and the end portion 129, the plurality of storage electrode lines 131 including the storage electrodes 133a and 133b, and the light blocking member ( 122).

And a gate insulating layer 140 made of silicon nitride (SiNx) on the gate line 121, the storage electrode line 131, and the light blocking member 122, an intrinsic amorphous silicon (a-Si) layer 150 which is not doped with impurities, and An amorphous silicon (n + a-Si) layer 160 doped with impurities is formed.

Subsequently, the data metal layer 170 is formed on the amorphous silicon layer 160 doped with impurities by a sputtering method.

As shown in FIGS. 7 and 8, the photoresist film is formed on the data metal layer 170, and then exposed and developed to form the photoresist patterns 52 and 54 having different thicknesses.

Here, for convenience of description, the data metal layer 170 of the portion where the wiring is to be formed, the amorphous silicon layer 160 doped with impurities, the intrinsic amorphous silicon layer 150 are referred to as the wiring portion A, and the gate electrode 124 The portion where the channel is formed above is called a channel portion B, and the region excluding the wiring portion A and the channel portion B is called the remaining portion C.

 Among the photoresist patterns 52 and 54, the first photoresist pattern 52 positioned in the wiring portion A is formed thicker than the second photoresist pattern 54 positioned in the channel portion B, and the photoresist of the remaining portion C is Remove everything. In this case, the ratio of the thickness of the first photoresist pattern 52 to the thickness of the second photoresist pattern 54 should be different depending on the process conditions in the etching process, which will be described later. It is preferable to set it as 1/2 or less of the thickness of 1 photosensitive film pattern 52.

As described above, there may be various methods of forming the thickness of the photoresist film differently according to the position. A semi-transparent area as well as a transparent area and a light blocking area may be formed in the exposure mask. For example. The semi-transmissive region includes a slit pattern, a lattice pattern, or a thin film having a medium transmittance or a medium thickness. When using the slit pattern, it is preferable that the width of the slits and the interval between the slits are smaller than the resolution of the exposure machine used for the photographic process. Another example is to use a photoresist film that can be reflowed. That is, a thin portion is formed by forming a reflowable photoresist pattern with a normal mask having only a transparent region and a light shielding region and then reflowing so that the photoresist film flows into an area where no photoresist remains.

 Subsequently, as illustrated in FIGS. 9 and 10, the data metal layer 170 exposed to the remaining portion C is removed by wet etching using the first photoresist pattern 52 to open the opening 176H. The data metal patterns 171, 174, and 179 having the same as FIG.

Next, dry etching the amorphous silicon layer 160 and the intrinsic amorphous silicon layer 150 doped with impurities remaining in the remaining portion C using the data metal patterns 171, 174, and 179 as masks. do.

Next, the second photoresist pattern 54 present in the channel portion B is removed using an etch back process. At this time, the thickness of the first photosensitive film pattern 52 also becomes somewhat thin.

11 to 13, the first metal photoresist pattern 52 from which the second photoresist pattern 54 is removed is wet-etched with a mask to form the data metal pattern 174 with the source electrode 173. The amorphous silicon pattern 164 doped with impurities is exposed in the channel region between the source electrode 173 and the drain electrode 175.

Subsequently, the first photosensitive film pattern 52 is removed.

Thereafter, the amorphous silicon pattern 164 doped with impurities in the channel region is dry-etched.

Next, as shown in FIGS. 14 to 16, the passivation layer 180 is formed to cover the protrusion 154 of the semiconductor that is not covered by the data line 171 and the drain electrode 175.

Next, the protective film 180 is etched to form a plurality of contact holes 181, 182, 184, 185, and 186.

Finally, as shown in FIGS. 1 to 3, a transparent conductive material such as ITO or IZO is deposited on the passivation layer 180 by sputtering, and then patterned to form the pixel electrode 191 and the contact auxiliary members 81 and 82. The connecting leg 84 and the connecting member 86 are formed.

As described above, the light blocking member can be prevented from irradiating light to the semiconductor under the data line, so that no leakage current or the like is generated. In addition, by connecting the light blocking member and the data line to make the voltage of the light blocking member and the data line the same, no additional parasitic capacitance is generated, so that the load of the data line is not increased or the signal transmission speed is not reduced.

Although 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 the invention.

Claims (6)

Board, A gate line formed on the substrate, A light blocking member formed on the substrate and separated from the gate line, A gate insulating film formed on the gate line, A semiconductor formed on the gate insulating layer and overlapping the light blocking member; A data line formed on the semiconductor and including a source electrode, A drain electrode formed on the semiconductor and facing the source electrode, A protective film formed on the data line and the drain electrode, A pixel electrode formed on the passivation layer and electrically connected to the drain electrode, and A connection member formed on the passivation layer and connecting the light blocking member and the data line; Thin film transistor display panel. In claim 1, And a resistive contact member formed between the semiconductor and the data line. Thin film transistor display panel. In claim 1, The semiconductor may include a first portion having a plane shape substantially the same as the data line and the drain electrode, and a second portion not covered with the data line and the drain electrode and positioned between the source electrode and the drain electrode. Thin film transistor display panel. In claim 1, The ohmic contact has the same planar shape as the data line and the drain electrode. Thin film transistor display panel. In claim 1, The data line and the semiconductor have an opening exposing the light blocking member, the passivation layer has a contact hole exposing the opening, and the connection member connects the data line and the light blocking member through the contact hole and the opening. Thin film transistor array panel. In claim 5, The contact hole exposes a surface above the data line around the opening, and the connection member also contacts the upper surface of the data line exposed through the contact hole together with the side of the data line exposed through the opening. Thin film transistor display panel.

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