KR20060028968A - Thin film transistor array panel and manufacturing method thereof - Google Patents

Abstract

In the method of manufacturing a thin film transistor array panel according to the present invention, forming an amorphous silicon layer on an insulating substrate, forming a metal layer under the insulating substrate, irradiating a laser on the amorphous silicon layer to form the amorphous silicon layer as a polycrystalline silicon layer It is preferable to include the step of forming. Accordingly, the method of manufacturing the thin film transistor array panel according to the present invention has an advantage of increasing the time that the amorphous silicon layer is irradiated to the laser to improve the crystallization characteristics by forming a metal layer serving as a reflective layer of the laser under the substrate.

Grain, polysilicon layer, liquid crystal display, laser, metal layer

Description

Thin film transistor array panel and manufacturing method therefor {THIN FILM TRANSISTOR ARRAY PANEL AND MANUFACTURING METHOD THEREOF}

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 to 11 are diagrams for describing a method of manufacturing a thin film transistor array panel according to an exemplary embodiment of the present invention.

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

FIG. 13 is a cross-sectional view of the thin film transistor array panel of FIG. 12 taken along the line XIII-XIII ′,

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

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

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

FIG. 17 is a cross-sectional view of the thin film transistor array panel of FIG. 16 taken along lines XVII-XVII 'and XVII'-XVII' '.

<Description of Symbols for Main Parts of Drawings>

110: substrate 121, 129: gate line

124: gate electrode 140: gate insulating film

151 and 154 semiconductor 161 and 165 resistive contact members

171, 179: data line 173: source electrode

175: drain electrode 30: metal layer

The present invention relates to a thin film transistor array panel and a method of manufacturing the same.

The liquid crystal display is one of the most widely used flat panel display devices. The liquid crystal display includes two display panels on which a field generating electrode is formed and a liquid crystal layer interposed therebetween. It is a display device which controls the transmittance | permeability of the light which passes through a liquid crystal layer by rearranging.

Among the liquid crystal display devices, a field generating electrode is provided in each of two display panels. Among them, a liquid crystal display device having a structure in which a plurality of pixel electrodes are arranged in a matrix form on one display panel and one common electrode covering the entire display panel on the other display panel is mainstream. The display of an image in this liquid crystal display device is performed by applying a separate voltage to each pixel electrode. To this end, a thin film transistor (TFT), which is a three-terminal device for switching a voltage applied to the pixel electrode, is connected to each pixel electrode and applied to a gate line and a pixel electrode that transmits a signal for controlling the thin film transistor. Install data lines that carry voltage on the display panel.

The thin film transistor has an amorphous silicon layer (a-Si) or a polycrystalline silicon layer (poly-Si) as a semiconductor layer, and a top gate method according to the relative position of the gate electrode and the semiconductor layer. And a bottom gate method. In the case of a polysilicon thin film transistor array panel, a top gate method in which a gate electrode is located above the semiconductor layer is mainly used. In the top gate method, a polycrystalline silicon layer is formed on an insulating substrate, a gate insulating film is formed on the polycrystalline silicon layer, and a gate line and a storage electrode line are formed on the gate insulating film.

The thin film transistor array panel using polycrystalline silicon has a higher charge mobility than the conventional thin film transistor array panel using amorphous silicon, and thus implements a liquid crystal display (Chip On Glass, COG) having a driving circuit inside the liquid crystal panel. This is possible and development of high resolution and high definition products is possible.

Among these, the crystallization process of converting the amorphous silicon layer into the polycrystalline silicon layer is a key process in the manufacturing process of the poly thin film transistor array panel, and determines threshold voltage (Vth) and charge mobility (mobility) values that affect the TFT characteristics. Is an absolute factor.

In particular, the electrical properties of the polycrystalline silicon layer are greatly influenced by the grain size. That is, as the grain size increases, the field effect mobility also increases.

Currently, a method using a laser is widely used as a method for crystallization to poly-silicon (poly-Si), and an ELA (Eximer Laser Annealing) crystallization method and a SLS (Sequential Lateral Solidification) crystallization method are used.

This laser crystallization process has a very important influence on the characteristics of the thin film transistor of the liquid crystal display device having a polycrystalline silicon layer. That is, when the grain size of the polysilicon layer is small or non-uniform, the characteristics of the thin film transistors are caused.

SUMMARY OF THE INVENTION The present invention provides a thin film transistor array panel having a large grain size and a uniform polycrystalline silicon layer and a method of manufacturing the same.

The thin film transistor array panel according to the present invention is formed on an insulating substrate, a polycrystalline silicon layer formed on the insulating substrate and including a source region, a drain region and a channel region, a metal layer formed under the insulating substrate, and the polycrystalline silicon layer. A gate insulating film, a gate line formed on the gate insulating film, the gate line including a gate electrode partially overlapping the channel region, an interlayer insulating film formed on the gate line, and a source electrode formed on the interlayer insulating film and connected to the source region. A data line including a data line, a drain electrode formed on the interlayer insulating layer and connected to the drain region, a passivation layer formed on the data line and the drain electrode, and a pixel electrode formed on the passivation layer and connected to the drain electrode. Containing It is preferable.

In addition, the metal layer preferably contains chromium.

In addition, the method of manufacturing a thin film transistor array panel according to the present invention may include forming an amorphous silicon layer on an insulating substrate, forming a metal layer under the insulating substrate, and irradiating a laser on the amorphous silicon layer to irradiate the amorphous silicon layer. It is preferable to include the step of forming a polycrystalline silicon layer.

The method may further include forming a gate insulating film on the polycrystalline silicon layer, forming a gate line including a gate electrode on the gate insulating film, and forming a source region, a drain region, and a channel region on the polycrystalline silicon layer. Forming an interlayer insulating film over a line, etching the interlayer insulating film and the gate insulating film to form a first contact hole and a second contact hole exposing the source region and the drain region, and forming the first contact hole on the interlayer insulating film And forming a data line including a source electrode connected to the source region through a sphere and a drain electrode connected to the drain region through the second contact hole.

The method may further include forming a passivation layer on the data line, forming a third contact hole exposing the drain electrode on the passivation layer, and forming a pixel electrode connected to the drain electrode through the third contact hole on the passivation layer. It is preferable to include the step of.                     

In addition, the amorphous silicon layer is preferably formed of a polycrystalline silicon layer using ELA or SLS.

In addition, the metal layer preferably contains chromium.

In addition, the thin film transistor array panel according to the present invention is formed on an insulating substrate, the polycrystalline silicon layer formed on the insulating substrate and including a source region, a drain region and a channel region, a metal layer formed under the insulating substrate, on the polycrystalline silicon layer A gate insulating layer formed on the gate insulating layer, a gate line overlapping the channel region and a portion of the gate insulating layer, a data metal piece positioned at a predetermined distance apart from a neighboring gate line and extending in a direction perpendicular to the gate line; A passivation layer formed on a line and a data metal piece, a data connection portion formed on the passivation layer and electrically connecting the data metal piece through a contact hole to intersect the gate line, and formed on the passivation layer and connected to the drain region through a contact hole. Pixel To include a polar are preferred.

Then, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can 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.

Hereinafter, a thin film transistor array panel and a method of manufacturing the same according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.

First, 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 and 2.

1 is a layout view of a thin film transistor array panel according to an exemplary embodiment of the present invention, and FIG. 2 is a cross-sectional view of the thin film transistor array panel of FIG. 1 taken along line II-II ′.

1 and 2, a blocking layer 111 made of silicon oxide (SiO ₂ ) or silicon nitride (SiNx) is formed on the transparent insulating substrate 10. The polycrystalline silicon layer 150 including the source region 153, the drain region 155, the channel region 154, and the lightly doped drain 152 is formed on the blocking layer 111.

Here, the blocking layer 111 may improve the adhesion between the insulating substrate 110 and the polycrystalline silicon layer 30, and prevent the conductive impurities present in the insulating substrate 110 from diffusing into the polycrystalline silicon layer 150. It plays a role.

A metal layer 30 made of chromium (Cr) or the like is formed under the insulating substrate 110.                     

The metal layer 30 serves as a reflective layer when irradiating a laser for forming the polysilicon layer 150 to increase the time for which the amorphous silicon layer 150A is irradiated to the laser by about two times.

Therefore, the metal layer 30 serves to make the grain size large and uniform by lowering the cooling rate of the polycrystalline silicon layer 150.

That is, the size of the grain (grain) that determines the characteristics of the thin film transistor array panel using polycrystalline silicon is determined by the crystallization energy and the cooling rate (cooling rate), for this purpose, the thin film transistor according to an embodiment of the present invention and its fabrication In the method, the metal layer 30 serving as the reflective layer of the laser is formed under the substrate 110 to increase the grain size.

 The lightly doped region 152 prevents leakage current or punch through. The source region 153 and the drain region 155 are heavily doped with N-type or P-type conductive impurities, and the channel region 154 is not doped with impurities.

The gate insulating layer 140 is formed on the polysilicon layer 150.

In addition, a gate line 121 extending in one direction is formed on the gate insulating layer 140, and a portion of the gate line 121 extends to overlap the channel region 154 of the second polysilicon layer 150. A portion of the overlapping gate line 121 is used as the gate electrode 124 of the thin film transistor. One end of the gate line 121 may be formed wider than the width of the gate line 121 in order to connect to an external circuit (not shown).                     

In addition, the storage electrode line 131 for increasing the storage capacitance of the pixel is parallel to the gate line 121 and is formed in the same layer with the same material. A portion of the storage electrode line 131 overlapping the polycrystalline silicon layer 150 becomes the storage electrode 133, and the polycrystalline silicon layer 150 overlapping the storage electrode 133 becomes the storage electrode region 157.

The gate line 121 and the storage electrode line 131 include a conductive film formed of a silver-based metal such as silver (Ag) or a silver alloy having a low resistivity, or an aluminum-based metal such as aluminum (Al) or an aluminum alloy. In addition to conductive films, chromium (Cr), titanium (Ti), tantalum (Ta), molybdenum (Mo) and alloys thereof with good physical, chemical and electrical contact properties with other materials, in particular ITO or IZO [see: Molybdenum-Tungsten (MoW) alloy] may have a multilayer film structure including another conductive film. An example of the combination of the lower layer and the upper layer is chromium / aluminum-neodymium (Nd) alloy.

An interlayer insulating layer 601 is formed on the gate insulating layer 140 on which the gate line 121 and the storage electrode line 131 are formed. The insulating film 601 is formed of a double layer made of SiO ₂ / SiN. If the SiO ₂ formed in the SiO ₂ / SiN-layer rather than a single layer is improved and the reliability of the thin film transistor than when formed in a SiO ₂ single layer.

The interlayer insulating layer 601 includes first and second contact holes 141 and 142 exposing the source region 153 and the drain region 155, respectively.

A data line 171 is formed on the interlayer insulating layer 601 to cross the gate line 121 and define a pixel area. A portion or the branched portion of the data line 171 is connected to the source region 153 through the first contact hole 141 and the portion connected to the source region 153 is the source electrode 173 of the thin film transistor. Used. One end of the data line 171 may be formed wider than the width of the data line 171 to be connected to an external circuit (not shown).

A drain electrode 175 is formed on the same layer as the data line 171 and is separated from the source electrode 173 and connected to the drain region 155 through the second contact hole 142.

The data line 171 and the drain electrode 175 are materials having excellent physical, chemical, and electrical contact properties with indium zinc oxide (IZO) or indium tin oxide (ITO), such as molybdenum (Mo) and molybdenum alloys. Tungsten (MoW) alloy]. The data line 171 and the drain electrode 175 may also be a conductive film made of a silver metal or an aluminum metal. In addition to the conductive film, chromium (Cr), titanium (Ti), tantalum (Ta), and molybdenum may be used. It may have a multilayer film structure including another conductive film made of (Mo) and an alloy thereof.

The protective film 602 is formed of an organic film, an inorganic film, or the like on the interlayer insulating film 601 including the data line 171 and the drain electrode 175.

The passivation layer 602 has a third contact hole 143 exposing the drain electrode 175. A transmissive electrode 192, which is a pixel electrode made of ITO, is formed on the passivation layer 602.                     

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

3 to 11 illustrate a method of manufacturing a thin film transistor array panel according to an exemplary embodiment of the present invention.

First, as shown in FIG. 3, the blocking layer 111 is formed on the transparent insulating substrate 110. In this case, glass, quartz, sapphire, or the like may be used as the transparent insulating substrate 110, and the blocking layer 111 is formed by depositing silicon oxide (SiO ₂ ) or silicon nitride (SiNx). Low barrier chemical vapor deposition (LPCVD) and plasma enhanced chemical vapor deposition (PECVD) are used to form the barrier layer 111. In the LPCVD method, the deposition temperature is 550 ° C. or higher, and the PECVD method uses a SiF 4 / SiH 4 / H 2 mixed gas to perform deposition at 400 ° C. or lower.

Then, an amorphous silicon layer 150A is formed on the top surface of the blocking layer 111. The amorphous silicon layer 150A is formed by depositing amorphous silicon by a chemical vapor deposition (CVD) method.

Here, the blocking layer 111 may improve the adhesion between the insulating substrate 110 and the polycrystalline silicon layer 30, and prevent the conductive impurities present in the insulating substrate 110 from diffusing into the polycrystalline silicon layer 150. It plays a role.

Next, as shown in FIG. 4, the metal layer 30 is formed under the insulating substrate 110 by chromium (Cr) or the like.

The amorphous silicon layer 150A is cooled after melting by cooling the amorphous silicon layer 150A by laser annealing (ELA) crystallization or sequential lateral solidification (SLS) crystallization. Is formed.

In this case, the metal layer 30 serves as a reflective layer when irradiating a laser for forming the polysilicon layer 150, thereby increasing the time for which the amorphous silicon layer 150A is irradiated to the laser by about two times.

That is, while the laser irradiation time to the amorphous silicon layer 150A was about 30 ns in the related art, in one embodiment of the present invention, the laser irradiation time to the amorphous silicon layer 150 A is increased to about 60 ns to improve crystallization characteristics. .

As such, the metal layer 30 serves to make the grain size large and uniform by lowering the cooling rate of the polycrystalline silicon layer 150.

The size of grain, which influences the characteristics of the thin film transistor array panel using polycrystalline silicon, is determined by crystallization energy and cooling rate, and for this purpose, in the manufacturing method of the thin film transistor according to an embodiment of the present invention, The metal layer 30 serving as the reflective layer of the substrate 110 is formed under the substrate 110 to increase the time that the amorphous silicon layer 150A is exposed to the laser to make the grain size large and uniform.

Next, as shown in FIG. 5, the polycrystalline silicon layer 150 is patterned by a photolithography method. The gate insulating layer 140 is formed on the polysilicon layer 150. The gate insulating layer 140 is formed by depositing an insulating material such as silicon oxide (SiO ₂ ) to a thickness of 500 to 3000 GPa by PECVD or LPCVD.

 Next, as shown in FIG. 6, the gate conductive layer 120A is formed on the gate insulating layer 140. The gate conductive layer 120A is formed by depositing an aluminum-containing metal layer such as aluminum (Al) or aluminum neodymium (AlNd) on the top surface of the gate insulating layer 140. A chromium layer is deposited on the gate conductive layer 120A, and a photoresist pattern is formed on the chromium layer. The chromium (Cr) layer pattern 58 is formed using the photosensitive film pattern as a mask. The chromium layer pattern 58 is formed in a pattern longer than the gate electrode 124 by a predetermined length to form a lightly doped region to be described later.

Next, as shown in FIG. 7, the gate conductive layer 120A is patterned using the chromium layer pattern 58 as a mask to form the gate electrode 124 and the gate line 121 on the gate insulating layer 140. At the same time, the sustain electrode 133 and the sustain electrode line 131 are formed. In this case, by extending the etching time of the gate conductive layer 120A, the gate conductive layer is etched more, so that the width of the gate electrode 123 is narrower than the width of the chromium layer pattern 58. The source region 153, the drain region 155, and the channel region 154 are formed by implanting a p-type or n-type conductive impurity onto the polysilicon layer 150 using the chromium layer pattern 58 as a mask. do. The channel region 154 is a region that is not doped with impurities and is positioned under the gate electrode 124 and separates the source region 153 and the drain region 155.

As shown in FIG. 8, after removing the chromium layer pattern 58, the low concentration doped region 152 is implanted by injecting a low concentration of p-type or n-type conductive impurities using the gate electrode 124 as a mask. Form. That is, the lightly doped region 152 is formed between the source region 153 and the channel region 154 and between the drain region 153 and the channel region 154.

The formation of the gate lines 121 and 124 and the storage electrode lines 131 and 133, the implantation of p-type and n-type conductive impurities into the polysilicon layer 150, and the formation of the low concentration doped region will be described in more detail. Same as

In the photolithography process using a photosensitive layer, the gate conductive layer 120A of the p-type thin film transistor region is etched to form a gate line (not shown) of the p-type thin film transistor, and then p-type impurity is implanted to inject the p-type thin film transistor. Source regions, drain regions, and channel regions are formed. At this time, like the liquid crystal display panel, the portion where the n-type thin film transistor is to be formed is covered and protected by the photosensitive layer. Then, the photosensitive layer is removed, and a gate conductive layer is formed in the portion where the n-type thin film transistor is to be formed.

The mask metal layer is formed to cover the gate line of the p-type thin film transistor and the gate conductive layer of the portion where the n-type thin film transistor is to be formed. The mask metal layer is a layer for patterning a lower layer and forming a mask for doping ions. The mask metal layer may be etched with the same etching solution as the gate conductive layer, and metals having different etching ratios may be used. In the present invention, a chromium layer is used as the mask metal layer.

Subsequently, a mask pattern wider than the gate lines 121 and 124 and the gate line width of the n-type thin film transistor is etched by etching the gate conductive layer 120A and the mask metal layer of the n-type thin film transistor region in a photolithography process using another photosensitive layer. N-type impurities are implanted using the mask pattern as a mask to form the source region 153, the drain region 155, and the channel region 154 of the n-type thin film transistor. At this time, the portion where the p-type thin film transistor is formed is covered and protected by the mask metal layer. The channel region 154 is a region where impurities are not implanted and is positioned below the gate electrode 124 and separates the source region 153 and the drain region 155. Next, after removing the mask pattern, the n-type impurities are doped at low concentration to form a low concentration doped region. The order of forming the n-type and p-type thin film transistor regions may be changed.

Next, as shown in FIG. 9, an insulating material is stacked on the entire surface of the insulating substrate 110 on which the source region 153, the drain region 155, and the channel region 154 are formed to form the interlayer insulating layer 601. do. The interlayer insulating film 601 is preferably formed of a double layer by first forming a silicon oxide (SiO ₂ ) layer and then forming a silicon nitride (SiNx) layer.

Next, as shown in FIG. 10, the interlayer insulating film 601 formed of a double layer is etched by plasma, so that the source electrode 173 and the drain electrode 175 and the source region 153 and the drain region 155 of the polysilicon layer are etched. ) Forms a first contact hole 141 and a second contact hole 142 for contacting, respectively.

Next, as shown in FIG. 11, the data line 171 and the drain electrode 175 including the source electrode 173 are formed on the interlayer insulating film 601. The source electrode 173 of the data line 171 is connected to the source region 153 through the first contact hole 141, and one end of the drain electrode 175 is connected to the drain region through the second contact hole 142. 155 is connected. The data line 171 is formed to vertically cross the gate line 121, and a pixel region in which a pixel electrode to be described later is formed is defined by the data line 171 and the gate line 121.

The protective film 602 is formed of an organic film or an inorganic film on the interlayer insulating film 601.

Next, as shown in FIG. 2, a third contact hole 143 exposing the drain electrode 175 is formed in the passivation layer 602. In addition, ITO is deposited on the passivation layer 601 and patterned to form the pixel electrode 192. In this case, the other end of the drain electrode 175 is connected to the pixel electrode 192 through the third contact hole 143.

Meanwhile, the polycrystalline silicon layer applied to the method of manufacturing a thin film transistor array panel for a transmissive liquid crystal display device having a polycrystalline silicon layer according to an embodiment of the present invention may be applied to the method for manufacturing a thin film transistor array panel for a transflective liquid crystal display device having a polycrystalline silicon layer. Do.

Hereinafter, a thin film transistor array panel for a transflective liquid crystal display device having a polycrystalline silicon layer according to another embodiment of the present invention will be described in detail with reference to the accompanying drawings.

12 is a layout view of a thin film transistor array panel according to another exemplary embodiment, and FIG. 13 is a cross-sectional view of the thin film transistor array panel of FIG. 12 taken along the line XIII-XIII ′.

12 and 13, a blocking layer 111 made of silicon oxide (SiO ₂ ) or silicon nitride (SiNx) is formed on the transparent insulating substrate 10. The polycrystalline silicon layer 150 including the source region 153, the drain region 155, the channel region 154, and the lightly doped drain 152 is formed on the blocking layer 111.

Here, the blocking layer 111 may improve adhesion between the insulating substrate 110 and the polycrystalline silicon layer 150, and prevent the conductive impurities present in the insulating substrate 110 from diffusing into the polycrystalline silicon layer 150. It plays a role.

A metal layer 30 made of chromium (Cr) or the like is formed under the insulating substrate 110.

The metal layer 30 serves as a reflective layer when irradiating a laser for forming the polysilicon layer 150 to increase the time for which the amorphous silicon layer 150A is irradiated to the laser by about two times.

Therefore, the metal layer 30 serves to make the grain size large and uniform by lowering the cooling rate of the polycrystalline silicon layer 150.

That is, the size of the grain (grain) that determines the characteristics of the thin film transistor array panel using polycrystalline silicon is determined by the crystallization energy and the cooling rate (cooling rate), for this purpose, the thin film transistor according to an embodiment of the present invention and its fabrication In the method, the metal layer 30 serving as the reflective layer of the laser is formed under the substrate 110 to increase the grain size.

The lightly doped region 152 prevents leakage current or punch through. The source region 153 and the drain region 155 are heavily doped with N-type or P-type conductive impurities, and the channel region 154 is not doped with impurities.

A gate insulating layer 140 is formed on the substrate 110 including the polysilicon layer 150.

The gate line 121 is formed to extend in one direction on the gate insulating layer 140, and a portion of the gate line 121 extends to overlap the channel region 154 of the polysilicon layer 150. A portion of the gate line 121 is used as the gate electrode 124 of the thin film transistor. One end of the gate line 121 may be formed wider than the width of the gate line 121 in order to connect to an external circuit (not shown).

In addition, the storage electrode line 131 for increasing the storage capacitance of the pixel is parallel to the gate line 121 and is formed in the same layer with the same material. A portion of the storage electrode line 131 overlapping the polycrystalline silicon layer 150 becomes the storage electrode 133, and the polycrystalline silicon layer 150 overlapping the storage electrode 133 becomes the storage electrode region 157.

The gate line 121 and the storage electrode line 131 include a conductive film formed of a silver-based metal such as silver (Ag) or a silver alloy having a low resistivity, or an aluminum-based metal such as aluminum (Al) or an aluminum alloy. In addition to conductive films, chromium (Cr), titanium (Ti), tantalum (Ta), molybdenum (Mo) and alloys thereof with good physical, chemical and electrical contact properties with other materials, in particular ITO or IZO [see: Molybdenum-Tungsten (MoW) alloy] may have a multilayer film structure including another conductive film. An example of the combination of the lower layer and the upper layer is a chromium / aluminum-neodymium (Nd) alloy.

An interlayer insulating layer 601 is formed on the gate insulating layer 140 on which the gate line 121 and the storage electrode line 131 are formed. The insulating film 601 is formed of a double layer made of SiO ₂ / SiN. If the SiO ₂ formed in the SiO ₂ / SiN-layer rather than a single layer is improved and the reliability of the thin film transistor than when formed in a SiO ₂ single layer.

The interlayer insulating layer 601 includes first and second contact holes 141 and 142 exposing the source region 153 and the drain region 155, respectively.

A data line 171 is formed on the interlayer insulating layer 601 to cross the gate line 121 and define a pixel area. A portion or the branched portion of the data line 171 is connected to the source region 153 through the first contact hole 141 and the portion connected to the source region 153 is the source electrode 173 of the thin film transistor. Used. One end of the data line 171 may be formed wider than the width of the data line 171 to be connected to an external circuit (not shown).

A drain electrode 175 is formed on the same layer as the data line 171 and is separated from the source electrode 173 and connected to the drain region 155 through the second contact hole 142.

The data line 171 and the drain electrode 175 are materials having excellent physical, chemical and electrical contact properties with indium zinc oxide (IZO) or indium tin oxide (ITO), such as molybdenum (Mo) and molybdenum alloys. Tungsten (MoW) alloy]. The data line 171 and the drain electrode 175 may also be a conductive film made of a silver metal or an aluminum metal. In addition to the conductive film, chromium (Cr), titanium (Ti), tantalum (Ta), and molybdenum may be used. It may have a multilayer film structure including another conductive film made of (Mo) and an alloy thereof.

The passivation layer 602 is formed on the interlayer insulating layer 601 including the data line 171 and the drain electrode 175.

The passivation layer 602 has a third contact hole 143 exposing the drain electrode 175. An embossing 50 having a concave-convex shape is formed on the surface of the protective film 602. Embossing 50 improves reflectivity when using reflective electrodes.

A transmissive electrode 192 made of ITO is formed on the passivation layer 602.

A reflective electrode 194 made of a metal such as aluminum-neodymium (AlNd) and connected to the drain electrode 175 through the third contact hole 143 is formed on the transmission electrode 192. The reflective electrode 194 and the transmission electrode 192 are called pixel electrodes. In addition, a transmission window 195 is formed in the reflective electrode 194, and only the transmission electrode 192 exists in the transmission window 195. The transmission window 195 is used as a passage through which the light from the backlight can pass when used in the transmission type, and transmits the light transmitted through the transmission electrode 192 through the transmission window 195 to the liquid crystal.

In another embodiment of the present invention, the data connector 171b and the pixel electrode 190 are formed on the same layer using the same material, and the pixel electrode 190 and the data connector 171b are formed of the second polysilicon layer 150. Since the contact holes 161 and 162 for connecting to the source and drain regions 153 and 155 are formed at the same time, the number of masks can be reduced compared to other embodiments.

Next, a thin film transistor array panel according to another exemplary embodiment of the present invention will be described in detail with reference to FIGS. 14 and 15.

FIG. 14 is a layout view of a thin film transistor array panel according to another exemplary embodiment. FIG. 15 is a cross-sectional view of the thin film transistor array panel of FIG. 14 taken along lines XV-XV 'and XV'-XV'.

As shown in FIGS. 14 and 15, a blocking layer 111 made of silicon oxide (SiO ₂ ) or silicon nitride (SiNx) is formed on the transparent insulating substrate 10. The polycrystalline silicon layer 150 including the source region 153, the drain region 155, the channel region 154, and the lightly doped drain 152 is formed on the blocking layer 111.

Here, the blocking layer 111 may improve adhesion between the insulating substrate 110 and the polycrystalline silicon layer 150, and prevent the conductive impurities present in the insulating substrate 110 from diffusing into the polycrystalline silicon layer 150. It plays a role.

A metal layer 30 made of chromium (Cr) or the like is formed under the insulating substrate 110.

The metal layer 30 serves as a reflective layer when irradiating a laser for forming the polysilicon layer 150 to increase the time for which the amorphous silicon layer 150A is irradiated to the laser by about two times.

Therefore, the metal layer 30 serves to make the grain size large and uniform by lowering the cooling rate of the polycrystalline silicon layer 150.

That is, the size of the grain (grain) that determines the characteristics of the thin film transistor array panel using polycrystalline silicon is determined by the crystallization energy and the cooling rate (cooling rate), for this purpose, the thin film transistor according to an embodiment of the present invention and its fabrication In the method, the metal layer 30 serving as the reflective layer of the laser is formed under the substrate 110 to increase the grain size.

The gate insulating layer 140 is formed on the substrate 110 including the polysilicon layer 150. Gate lines 121 and 124 elongated in the horizontal direction are formed on the gate insulating layer 140, and a portion of the gate lines 121 and 124 extend in the vertical direction to partially overlap the second polycrystalline silicon layer 150. A portion of the gate lines 121 and 124 overlapping the second polycrystalline silicon layer 150 is used as the gate electrode 124.

One end portion (not shown) of the gate line 121 may be formed to be wider than the width of the gate lines 121 and 124 to receive a scan signal from an external circuit (not shown).

Further, the storage electrode lines 131 and 133 are formed in the same layer with the same material as the gate lines 121 and 124 so that the storage electrode lines 131 and 133 are formed to be parallel to the gate lines 121 and 124 and are positioned in parallel. A portion of the storage electrode lines 131 and 133 overlapping the polycrystalline silicon layer 150 becomes the storage electrode 133, and the polycrystalline silicon layer 150 positioned below the storage electrode 133 may have the storage electrode region 157. do.

In addition, the data metal piece 171a is formed on the same layer as the gate lines 121 and 124 and is formed to be separated from the gate lines 121 and 124 by a predetermined distance and extends in a direction perpendicular to the gate lines 121 and 124. . The data metal piece 171a is formed not to be connected to the gate lines 121 and 124 between two adjacent gate lines 121 and 124. In addition, the data metal piece 171a may enlarge and form one end portion 179 of one row of the data metal piece 171a located at the outermost side in order to receive an image signal from an external circuit (not shown).

The passivation layer 160 is formed on the gate insulating layer 140 including the gate lines 121 and 124 and the storage electrode lines 131 and 133.

The data connection part 171b, the pixel electrode 190, and the contact auxiliary member 82 are formed on the passivation layer 160. The data connection part 171b is formed to cross the gate lines 121 and 124 and the storage electrode lines 131 and 133 in the vertical direction.

The data metal piece 171a is connected to the data connection part 171b through the third contact hole 163 formed in the passivation layer 160, and the data connection part 171b is connected to the source region through the first contact hole 161. 153 is connected. That is, the data metal pieces 171a separated by the data connection part 171b are connected across the gate lines 121 and 124 and the storage electrode lines 131 and 133. In addition, the pixel electrode 190 is connected to the drain region 155 through the second contact hole 162 formed over the passivation layer 160 and the gate insulating layer 140, and the contact auxiliary member 82 is formed of a passivation layer (eg, a passivation layer). The fourth contact hole 164 formed at 160 is connected to the gate lines 121 and 124 and one end portion 179 of the data metal piece 171a, respectively.

The pixel electrode made of ITO on the passivation layer 160 is a transmissive electrode 190 and is used as a passage through which light from the backlight can pass.

The contact auxiliary member 82 is connected to the end portion 179 of the data line through the contact hole 162. The contact assisting member 82 is not essential to serve to protect adhesiveness between the end portion 179 of the data line 171 and an external device and to protect them, and application thereof is optional. In particular, when the driving circuit is formed together with the thin film transistor in the display area, it is not formed.

On the other hand, unlike the thin film transistor array panel for a transmissive liquid crystal display device having a polysilicon layer according to another embodiment, the polycrystalline silicon layer according to another embodiment may be applied to the thin film transistor array panel for a transflective liquid crystal display device having a polycrystalline silicon layer. . The thin film transistor array panel for the transflective liquid crystal display will be described in detail below with reference to FIGS. 16 and 17.

FIG. 16 is a layout view of a thin film transistor array panel according to another exemplary embodiment, and FIG. 17 is a cross-sectional view of the thin film transistor array panel of FIG. 16 taken along lines XVII-XVII 'and XVII'-XVII' '.

As shown in FIGS. 16 and 17, a blocking layer 111 made of silicon oxide (SiO ₂ ) or silicon nitride (SiNx) is formed on the transparent insulating substrate 10. The polycrystalline silicon layer 150 including the source region 153, the drain region 155, the channel region 154, and the lightly doped drain 152 is formed on the blocking layer 111.

Here, the blocking layer 111 may improve the adhesion between the insulating substrate 110 and the polycrystalline silicon layer 30, and prevent the conductive impurities present in the insulating substrate 110 from diffusing into the polycrystalline silicon layer 150. It plays a role.

A metal layer 30 made of chromium (Cr) or the like is formed under the insulating substrate 110.

The metal layer 30 serves as a reflective layer when irradiating a laser for forming the polysilicon layer 150 to increase the time for which the amorphous silicon layer 150A is irradiated to the laser by about two times.

Therefore, the metal layer 30 serves to make the grain size large and uniform by lowering the cooling rate of the polycrystalline silicon layer 150.

That is, the size of the grain (grain) that determines the characteristics of the thin film transistor array panel using polycrystalline silicon is determined by the crystallization energy and the cooling rate (cooling rate), for this purpose, the thin film transistor according to an embodiment of the present invention and its fabrication In the method, the metal layer 30 serving as the reflective layer of the laser is formed under the substrate 110 to increase the grain size.

An embossing 50 having an uneven shape is formed on the surface of the protective film 160. Embossing 50 improves reflectivity when using reflective electrodes.

A transmissive electrode 192 made of ITO is formed on the passivation layer 160.                     

It is connected to the drain region 155 through a second contact hole 162 formed of a metal such as aluminum-neodymium (AlNd) on the transmission electrode 192 and formed over the organic layer 160 and the gate insulating layer 140. Reflective electrode 194 is formed. The reflective electrode 194 and the transmission electrode 192 are called pixel electrodes. In addition, a transmission window 195 is formed in the reflective electrode 194, and only the transmission electrode 192 exists in the transmission window 195. The transmission window 195 is used as a passage through which the light from the backlight can pass when used in the transmission type, and transmits the light transmitted through the transmission electrode 192 through the transmission window 195 to the liquid crystal.

Although the preferred embodiments of the present invention have been described in detail above, those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Accordingly, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concept of the present invention as defined in the following claims also fall within the scope of the present invention.

The thin film transistor array panel according to the present invention and a method of manufacturing the same have an advantage of increasing the time that the amorphous silicon layer is irradiated to the laser to improve the crystallization characteristics by forming a metal layer serving as a reflective layer of the laser under the substrate.

Claims (8)

Insulation board, A polycrystalline silicon layer formed on the insulating substrate and including a source region, a drain region and a channel region, A metal layer formed under the insulating substrate, A gate insulating film formed on the polycrystalline silicon layer, A gate line formed on the gate insulating layer and including a gate electrode partially overlapping the channel region; An interlayer insulating film formed on the gate line, A data line formed on the interlayer insulating layer and including a source electrode connected to the source region; A drain electrode formed on the interlayer insulating layer and connected to the drain region; A protective film formed on the data line and the drain electrode, And a pixel electrode formed on the passivation layer and connected to the drain electrode. In claim 1, The metal layer may include chromium. Forming an amorphous silicon layer on the insulating substrate, Forming a metal layer under the insulating substrate, Irradiating a laser on the amorphous silicon layer to form the amorphous silicon layer as a polycrystalline silicon layer Method of manufacturing a thin film transistor array panel comprising a. In claim 3, Forming a gate insulating film on the polycrystalline silicon layer, Forming a gate line including a gate electrode on the gate insulating layer, Forming a source region, a drain region, and a channel region in the polycrystalline silicon layer, Forming an interlayer insulating film on the gate line; Etching the interlayer insulating layer and the gate insulating layer to form first and second contact holes exposing the source and drain regions; Forming a data line on the interlayer insulating layer, the data line including a source electrode connected to the source region through the first contact hole and a drain electrode connected to the drain region through the second contact hole; Method of manufacturing a thin film transistor array panel comprising a. In claim 3, Forming a passivation layer on the data line; Forming a third contact hole exposing the drain electrode on the passivation layer, And forming a pixel electrode connected to the drain electrode through the third contact hole on the passivation layer. In claim 3, And the amorphous silicon layer is formed of a polycrystalline silicon layer using ELA or SLS. In claim 3, And the metal layer comprises chromium. Insulation board, A polycrystalline silicon layer formed on the insulating substrate and including a source region, a drain region and a channel region, A metal layer formed under the insulating substrate, A gate insulating film formed on the polycrystalline silicon layer, A gate line formed on the gate insulating layer and partially overlapping the channel region; A data metal piece positioned a predetermined distance apart from the neighboring gate lines and extending in a direction perpendicular to the gate line; A protective film formed on the gate line and the data metal piece, A data connection part formed on the passivation layer and electrically connecting the data metal piece through a contact hole to cross the gate line; And a pixel electrode formed on the passivation layer and connected to the drain region through a contact hole.

Images