KR20080001212A - Array substrate for liquid crystal display device with driving circuit and method for fabricating of the same - Google Patents

Abstract

An array substrate for an LCD(Liquid Crystal Display) integrated with a driving circuit and a manufacturing method thereof are provided to manufacture the array substrate by performing a mask process five times, thereby reducing manufacturing time and costs and improving productivity and yields by simplifying processes. On a substrate, first to fourth amorphous silicon(a-Si) patterns, transparent conductive patterns, a pixel electrode(106) made from the same material and on the same layer as the transparent conductive pattern, and a first storage electrode(116) connected to the pixel electrode are formed. By crystallizing the first to third a-Si patterns, first to third semiconductor layers(114) of poly silicon are formed. A gate insulating layer is formed on the front of the first to third semiconductor layers, the first storage electrode and the pixel electrode. On the gate insulating layer, first to third gate electrodes(125) are respectively formed in the centers of the first to third semiconductor layers, and a second storage(127) electrode is formed to be corresponded to the first storage electrode. By performing n+ doping of a first dose, n- doping of a second dose and p+ doping of a third dose, an active layer(114a) which is not doped to the first and second semiconductor layers, an n+ doped n-type ohmic contact layer(114b), and an n- doped LDD(Light Doped Drain) layer(114c) are formed. An active layer which is not doped to the third semiconductor layer and a p+ doped p-type ohmic contact layer are formed. First to third source and drain electrodes(150a,150b) respectively contacted with the ohmic contact layer of the first to third semiconductor layers and spaced from each other are formed. A third storage electrode(153) connected to the first drain electrode and corresponding to the second storage electrode is formed.

Description

Array substrate for liquid crystal display device and manufacturing method thereof [Array substrate for liquid crystal display device with driving circuit and method for fabricating of the same}

1 is a schematic diagram of a general liquid crystal display device integrated with a driving circuit unit;

FIG. 2 is a cross-sectional view of a portion in which a switching thin film transistor STr and a storage capacitor StgC, which serve as a switching element of a pixel unit PA, are formed in a conventional array substrate for a liquid crystal display device having a driving circuit.

Fig. 3 is a cross-sectional view of an inverter having a CMOS structure of a drive circuit portion in a conventional drive circuit integrated liquid crystal display array substrate.

4A to 4D are plan views illustrating manufacturing steps of one pixel region in a pixel unit PA in an array substrate for a driving circuit-integrated liquid crystal display device according to the present invention.

5A to 5H are cross-sectional views of manufacturing steps for a portion cut along the cutting line VV of FIGS. 4A to 4D;

6A to 6H are cross-sectional views of manufacturing steps of an inverter having a CMOS structure of a drive circuit unit in an array substrate for a drive circuit-integrated liquid crystal display device according to the present invention.

<Description of Symbols for Main Parts of Drawings>

101 substrate 103 buffer layer

106: pixel electrode 105a: first transparent conductive pattern

110a and 110b: first and second buffer patterns 114: first semiconductor layer

114a: first active layer 114b: first n-type ohmic contact layer

114c: first LDD layer 116: first storage electrode

123: gate insulating film 125: first gate electrode

127: second storage electrode 135: protective layer

140a, 140b: first and second contact holes 150a: first source electrode

150b: first drain electrode 153: third storage electrode

P: pixel area PA: pixel part

PEA: Pixel electrode area STrA: Switching area

StgA: Storage Area

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to an array substrate for an integrated liquid crystal display device with a driving circuit unit and a manufacturing method thereof.

Recently, liquid crystal displays have been spotlighted as next generation advanced display devices having low power consumption, good portability, technology-intensive, and high added value.

The liquid crystal display device injects a liquid crystal between an array substrate including a thin film transistor (TFT) and a color filter substrate to obtain an image effect by using a difference in refractive index of light according to the anisotropy of the liquid crystal. Means an image display device by a non-light emitting element.

Currently, an active matrix liquid crystal display (AM ^- LCD) in which the thin film transistor and the pixel electrode are arranged in a matrix manner is attracting the most attention because of its excellent resolution and video performance.

Hydrogenated amorphous silicon (H) (hereinafter abbreviated as amorphous silicon (a-Si)) is mainly used as the thin film transistor device because low-temperature processing is possible, so that an inexpensive insulating substrate can be used. .

However, since hydrogenated amorphous silicon has a disordered atomic arrangement, weak Si-Si bonds and dangling bonds exist, and thus they are changed to a quasi-stable state when irradiated with light or applied with an electric field to be used as a thin film transistor device. Stability is a problem. In addition, the electrical characteristics (low field effect mobility: 0.1 to 1.0 cm 2 / V · s) are poor, making it difficult to use as a drive element constituting the drive circuit.

On the other hand, polysilicon may be used as a driving device because of its greater field effect mobility than amorphous silicon. When manufacturing an array substrate for a liquid crystal display device using the polysilicon, the driving device is included in the array substrate. By constructing, there is an advantage that the driving circuit part can be formed on one substrate.

1 is a schematic diagram of a liquid crystal display device including a driving device using a general polysilicon.

As shown in the drawing, the driving circuit section 3 and the pixel section 4 are simultaneously configured on the substrate 2.

The pixel portion 4 is positioned at the center of the substrate 2, and gate and data driving circuit portions 3a and 3b are positioned on one side of the pixel portion 4 and the other side not parallel thereto.

The pixel portion 4 includes a plurality of gate wires 6 connected to the gate driving circuit part 3a and a plurality of data wires 8 connected to the data driving circuit part 3b intersect each other. , The pixel electrode 10 is formed on the pixel region P defined by the intersection of 8, and the thin film transistor Tr connected to the pixel electrode 10 is positioned at the intersection of the two wires 6 and 8. do.

The gate and data driving circuit sections 3a and 3b are devices for supplying a display control signal and a data signal through the gate and data lines 6 and 8, respectively.

In addition, the gate and data driving circuit units 3a and 3b are connected to an external signal input terminal 12, and the gate and data wirings 6 and 8 are controlled by controlling an external signal input through the external signal input terminal 12. It serves to output.

The gate and the data driver circuits 3a and 3b are provided with an inverter as a driving element for properly outputting an input signal. The inverter is a CMOS mainly composed of a pair of p-type thin film transistors and n-type thin film transistors. (complementary metal ^- oxide semiconductor) is adopted.

The CMOS is a kind of semiconductor technology used in a driving circuit portion requiring high-speed signal processing. The CMOS uses a single electron by using extra electrons (n-type semiconductor) or negatively charged holes (p-type semiconductor) charged with negative electricity. By forming a conductor, it is used in a complementary manner to achieve a current gate by effective electrical control of the two types of semiconductors.

FIG. 2 is a cross-sectional view of a portion of a driving substrate integrated liquid crystal display device having a switching thin film transistor STr and a storage capacitor StgC serving as a switching element of a pixel unit PA. 3 shows a cross-sectional view of an inverter having a CMOS structure of a drive circuit section in a conventional array of drive circuit integrated liquid crystal display devices. For convenience of description, the switching region STrA, the storage capacitor StgC, and the storage region StgA are formed in the region where the switching element is formed in the pixel unit PA, and the region in which the CMOS structure inverter is formed in the driving circuit unit. The area DA and the region where the n-type thin film transistor is formed in the driving region are defined as the first region I and the region where the p-type thin film transistor is formed as the second region II.

First, referring to FIG. 2, as illustrated, a buffer layer 23 is formed over an entire surface of a transparent insulating substrate 20, and a first semiconductor made of polysilicon is formed in the switching region STrA. A layer 25 is formed, and a first storage electrode 26 made of polysilicon is formed in the storage region StgA. In this case, the first semiconductor layer 25 and the first storage electrode 26 are electrically connected to each other, although they are formed to be spaced apart from each other.

In addition, a gate insulating film 30 is formed on the first semiconductor layer 25 and the first storage electrode 26, and the first gate electrode 40 and the second storage electrode are respectively formed on the gate insulating film 30. 43 is formed. In this case, the first and second storage electrodes 26 and 43 and the gate insulating layer 30 formed therebetween form a storage capacitor StgC.

In addition, an interlayer insulating film 50 including first and second semiconductor layer contact holes 53a and 53b is formed on the first gate electrode 40 and the second storage electrode 43. The first and second semiconductor layers 25 are connected to the first semiconductor layer 25 through the first and second semiconductor layer contact holes 53a and 53b and spaced apart from each other on both sides of the first gate electrode 40. Source and drain electrodes 60 and 63 are formed. In this case, the first semiconductor layer 25, the gate insulating layer 30, the first gate electrode 40, the interlayer insulating layer 50, and the first source and drain electrodes 60 and 63 which are sequentially stacked may be a switching thin film transistor ( STr).

In addition, a passivation layer 70 including a drain contact hole 75 exposing a portion of the first drain electrode 63 is formed on the first source and drain electrodes 60 and 63. A pixel electrode 80 connected to the first drain electrode 63 is formed on the upper portion 70 through the drain contact hole 75.

In this case, the first semiconductor layer 25 and the region corresponding to the first gate electrode 30 may include a first active layer 25a made of pure polysilicon, and the first source and drain electrodes 60 and 63. each contacting portion is n ⁺ doped claim 1 n-type ohmic contact layer (25c), and n- doped at a low concentration between the first active layer (25a) and a 1 n-type ohmic contact layer (25c) to the polysilicon First lightly doped drain (LDD) layer 25b.

Meanwhile, the first storage electrode 26 connected to the first semiconductor layer 25 in the storage region StgA and made of polysilicon like the first semiconductor layer 25 is the first semiconductor layer 25. Like the n-type ohmic contact layer 25c, a high concentration of n + is doped to form a conductive material rather than a semiconductor layer.

Next, the structure of the CMOS of the driving circuit unit will be described with reference to FIG. 3.

As shown in the drawing, the buffer layer 23 is formed on the transparent insulating substrate 20, and the n-type semiconductor layer 28 and the p-type semiconductor layer 30 are formed to be spaced apart from each other by a predetermined distance therebetween. The gate insulating layer 30 is formed on the n-type and p-type semiconductor layers 28 and 29, respectively, and the second and third gate electrodes 45 and 47 are formed on the gate insulating layer 30, respectively. Formed.

In addition, third to upper portions of the second and third gate electrodes 45 and 47 expose the n-type and p-type semiconductor layers 28 and 29 to both sides of the second and third gate electrodes 45 and 47, respectively. An interlayer insulating film 50 including six semiconductor layer contact holes 55a, 55b, 58a, and 58b is formed, and the third to sixth semiconductor layer contact holes 55a, 55b, and upper portions of the interlayer insulating film 50. Second and third source and drain electrodes 65a and 65b and 68a and 68b are formed through 58a and 58b to contact the n-type and p-type semiconductor layers 28 and 29, respectively. A protective layer 70 is formed on the entire surface of the second and third source and drain electrodes 65a, 65b and 68a and 68b. In this case, the n-type semiconductor layer 28, the gate insulating film 30, the second gate electrode 45, the interlayer insulating film 50, and the second source and drain electrodes 65a and 65b that are sequentially stacked are n-type thin film transistors. (nTr), and the p-type semiconductor layer 29, the gate insulating film 30, the third gate electrode 47, the interlayer insulating film 50, and the third source and drain electrodes 68a and 68b are sequentially stacked. Constitutes a p-type thin film transistor (pTr).

 Meanwhile, the structure of the n-type and p-type semiconductor layers 28 and 29 will be described in more detail. The n-type semiconductor layer 28 has a second region corresponding to the second gate electrode 45. An active layer 28a, and a region in contact with the second source and drain electrodes 65a and 65b as the second n-type ohmic contact layer 28c, and the second n-type ohmic contact layer 28c The low-concentration n-doped region between the active layers 28a is composed of the second LDD layer 28b, and the p-type semiconductor layer 29 uses a positively charged carrier, and thus the n-type thin film Since the deterioration of the carrier and the leakage current are less affected than the transistor nTr, the region corresponding to the third gate electrode 47 is defined as the third active layer 29a without forming a separate LDD layer. Both side regions of the third active layer 29a are formed as the p-type ohmic contact layer 29c.

On the other hand, in the fabrication of an array substrate for a liquid crystal display device with integrated driving circuit unit having such a configuration, a semiconductor layer patterning process (# 1) / storage doping process (# 2) / n-doped gate forming process (# 3) / of polysilicon n + doping step (# 4) / p + doping step (# 5) / contact hole forming step (# 6) of interlayer insulating film (source and drain forming step (# 7) / drain contact hole forming step of protective layer (# 8) A total of nine mask processes of the pixel electrode forming process # 9 are included.

In this case, since each mask process includes a unit process such as photo resist coating, exposure using an exposure mask, development, and etching, manufacturing costs are increased as the mask process is added. And the process time increases, and the more the number of the process, the greater the possibility of failure increases, there is a problem of lowering the yield and productivity.

In order to solve the above problems, the present invention manufactures an array substrate for a polysilicon driving circuit-integrated liquid crystal display device with improved yield and productivity by reducing the number of masks and shortening the number of masks by reducing the number of masks by performing a total of five mask processes. It is an object to provide a method.

Another object of the present invention is to improve the aperture ratio by reducing the storage area in which the storage capacitor, which is a non-display area, is formed by proposing a structure to improve the storage capacity.

In order to achieve the above object, a method of manufacturing an array substrate for a drive circuit-integrated liquid crystal display device according to the present invention, the first to fourth amorphous silicon pattern and a transparent conductive pattern below and a transparent conductive pattern on the substrate, respectively; Forming a pixel electrode formed of the same material on the same layer as the first electrode and a first storage electrode connected to the pixel electrode; Crystallizing the first to third amorphous silicon patterns to form first to third semiconductor layers of polysilicon; Forming a gate insulating film over the first to third semiconductor layers and the first storage electrode and the pixel electrode; Forming first to third gate electrodes on each of central portions of the first to third semiconductor layers above the gate insulating layer, and simultaneously forming second storage electrodes to correspond to the first storage electrodes; A first dose of n + doping, a second dose of n + doping and a third dose of p + doping to form an active layer that is not doped in each of the first and second semiconductor layers, and an n + doped n-type ohmic Forming a contact layer, an n− doped LDD layer, and forming an undoped active layer and a p + doped p-type ohmic contact layer on the third semiconductor layer; Forming first to third source and drain electrodes that are in contact with and spaced apart from the ohmic contact layers of the first to third semiconductor layers, respectively, and are simultaneously connected to the first drain electrode and corresponding to the second storage electrode, respectively. Forming a storage electrode.

In this case, the first to fourth amorphous silicon patterns and a lower conductive conductive pattern are formed on the substrate, a pixel electrode made of the same material on the same layer as the transparent conductive pattern, and a first storage electrode connected to the pixel electrode. The method may include forming a transparent conductive material layer, a first buffer layer, and an amorphous silicon layer sequentially on the substrate; Forming a first photoresist pattern of a first thickness and a second photoresist pattern of a second thickness thinner than the first thickness over the amorphous silicon layer; Removing the amorphous silicon layer, the first buffer layer, and the transparent conductive material layer exposed to the outside of the first and second photoresist patterns to form first to fourth patterns having a triple layer structure; Removing the second photoresist pattern to expose a portion of the fourth pattern; Forming the pixel electrode of a transparent conductive material by removing an amorphous silicon pattern and a buffer pattern which form an uppermost layer and an intermediate layer among the exposed fourth patterns; Exposing the first to third amorphous silicon patterns that form the top layer of the first to third patterns by removing the first photoresist pattern, wherein the first photoresist having the first thickness Forming a second photoresist pattern having a pattern and a second thickness comprises: forming a photoresist layer over the amorphous silicon layer; Exposing the photoresist layer using an exposure mask having a light blocking region, a transmissive region, and a transflective region; Developing the exposed photoresist layer.

In addition, the crystallization is characterized by melting the first to fourth amorphous silicon pattern by irradiating a laser.

In addition, a first dose of n + doping, a second dose of n− doping and a third dose of p + doping are performed to undo each of the first and second semiconductor layers, respectively, and n + doped n. Forming an ohmic type contact layer, an n- doped LDD layer, and forming an undoped active layer and a p + doped p-type ohmic contact layer in the third semiconductor layer, the first to third gate electrode Is a doping mask and doped with a first dose of n-type impurities to form first to third n-type ohmic contact layers on both sides of the first to third semiconductor layers, respectively, and correspond to the first to third gate electrodes. Wherein the undoped portions form first to third active layers; Performing dry etching to remove predetermined widths of both sides of the first to third gate electrodes; Forming first to third LDD layers by doping n-type impurities having a second dose smaller than the first dose to the first to third actin layers exposed to the outside of the first to third gate electrodes. Wow; A photoresist pattern is formed on the first and second gate electrodes and the second storage electrode to cover the first and second semiconductor layers and the second storage electrode, and a third dose greater than the first dose is formed. Forming the third LDD layer and the third n-type ohmic contact layer formed on the third semiconductor layer as a p-type ohmic contact layer by doping the p-type impurity; Removing the photoresist pattern.

The forming of the first to third source and drain electrodes and the third storage electrode, which are in contact with the ohmic contact layers of the first to third semiconductor layers and spaced apart from each other, may include the first to third gate electrodes. Forming a protective layer having first to sixth contact holes exposing the first to second n-type ohmic contact layers and the p-type ohmic contact layer, respectively, on the second storage electrode; First to third source electrodes and first to third drains contacting and spaced apart from the first to second n-type ohmic contact layer and the p-type ohmic contact layer through the first to sixth contact holes on the protective layer; Forming an electrode.

The forming of the passivation layer having the first to sixth contact holes may include forming a pixel electrode contact hole exposing the pixel electrode, and forming the first to third source and drain electrodes. The step of allowing the first drain electrode to be electrically connected to the pixel electrode through the pixel electrode contact hole.

The method may further include forming a second buffer layer on the substrate before forming the first to fourth amorphous silicon patterns and the pixel electrode on the substrate.

In addition, the forming of the first to third gate electrodes may further include forming a gate wiring connected to the first gate electrode and extending in one direction, wherein the forming of the gate wiring may include And forming a common wiring connected to the second storage electrode and extending in parallel with the gate wiring. The forming of the first to third source and drain electrodes and the third storage electrode may include: And forming a data line connected to the first drain electrode and intersecting the gate line.

An array substrate for an integrated circuit liquid crystal display device according to the present invention includes: a pixel electrode and a first storage electrode formed of the first to fourth transparent conductive patterns and the same material formed on the substrate; First to fourth buffer patterns respectively formed on the first to fourth transparent conductive patterns; A semiconductor pattern formed on the first to third semiconductor layers and the fourth buffer pattern on the first to third buffer patterns; A gate insulating film formed over the first to third semiconductor layers and the pixel electrode; First to third gate electrodes formed on a central portion of the first to third semiconductor layers and corresponding to the first storage electrodes on the gate insulating layer; First to sixth contact holes formed on an entire surface of the first to third gate electrodes and the second storage electrodes, and exposing first to third semiconductor layers on both sides of the first to third gate electrodes; A protective layer formed; First to third source and drain electrodes formed to be in contact with the first to third semiconductor layers and spaced apart from each other through the first to sixth contact holes; And a third storage electrode formed on the same layer as the first to third source and drain electrodes to correspond to the second storage electrode.

In this case, the third storage electrode is connected to the first drain electrode.

The protective layer may further include a pixel electrode contact hole exposing a portion of the pixel electrode, wherein the first drain electrode is formed to contact the pixel electrode through the pixel electrode contact hole.

The gate insulating layer may further include: a gate wire connected to the first gate electrode and extending in one direction; A common wiring spaced apart from the gate wiring and connected to the second storage electrode is further formed. In this case, a data wiring connected to the first source electrode and intersecting the gate wiring is formed on the passivation layer. This is further formed.

The first and second semiconductor layers may have low concentrations on both sides of each of the first and second active layers, which are not doped, and the first and second active layers, respectively, corresponding to portions corresponding to the first and second gate electrodes. and n-doped first and second LDD layers, and a high concentration of n + doped first and second n-type ohmic contact layers outside each of the first and second LDD layers, wherein the third semiconductor layer comprises: The non-doped third active layer corresponding to the portion corresponding to the three gate electrode and a high concentration of p + doped p-type ohmic contact layer are formed on both sides of the third active layer.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

4A to 4D are plan views illustrating manufacturing process steps of one pixel area in the pixel unit PA in the array substrate for driving circuit-integrated liquid crystal display device according to the present invention, and FIGS. 5A to 5H illustrate FIGS. 4A to 4D. 6 is a cross-sectional view illustrating a process of manufacturing a cut portion along a cutting line V-V, and FIGS. 6A to 6H illustrate an inverter having a CMOS structure of a driving circuit unit in an array substrate for a liquid crystal display device with integrated driving circuit according to the present invention. Process cross-sectional view of manufacturing steps. For convenience of explanation, the switching region STrA, the storage capacitor StgC, and the storage region StgA and the pixel electrode are formed in the region where the switching thin film transistor STr element is formed in the pixel region P. A region in which the pixel electrode region PEA and the CMOS structure inverter of the driving circuit unit are formed is a driving region DA, and an region in which an n-type thin film transistor nTr is formed among the driving regions DA is formed. A region where the first region I and the p-type thin film transistor pTr are formed is defined as a second region II.

As shown in FIGS. 4A, 5A, and 6A, the first buffer layer 103 is formed by depositing silicon nitride (SiNx) or silicon oxide (SiO ₂ ), which is an inorganic insulating material, on the transparent insulating substrate 101. When the first buffer layer 103 recrystallizes amorphous silicon into polysilicon in a later process, alkali ions, such as potassium ions (K +) and sodium, present in the substrate 101 due to heat generated by laser irradiation or the like. Ions (Na +), etc. may occur, in order to prevent the film properties of polysilicon from being degraded by such alkali ions. In this case, the first buffer layer may be omitted depending on the material of the insulating substrate 101.

Next, a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO) is deposited on the buffer layer 103 to form a transparent conductive material layer 105, and subsequently the transparent conductive material. An inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (SiNx) is deposited on the material layer 105 to form a second buffer layer 109, and then pure amorphous silicon is deposited on the amorphous silicon layer 113. ).

Next, the photoresist layer (not shown) is exposed on the amorphous silicon layer 113 by using an exposure mask (not shown) having a light transmitting region, a blocking region, and a semi-transmissive region, and then developed the first photoresist layer. A first photoresist pattern 181a having a t1 is formed in the switching region STrA, the storage region StgA, and the first and second regions I and II, and at the same time, the first thickness t1. A second photoresist pattern 181b having a thinner second thickness t2 is formed in the pixel electrode region PEA in the pixel region P. Referring to FIG.

In this case, the exposure using the exposure mask having the transflective area used to form the photoresist patterns 181a and 181b having different thicknesses by performing a single mask process is referred to as diffraction exposure or halftone exposure. .

As shown in FIGS. 4A, 5B, and 6B, an amorphous silicon layer (113 of FIGS. 5A and 6A) exposed to the outside of the first and second photoresist patterns 181a and 181b and a second buffer layer below it (FIG. 5a, 6a 109 and the transparent conductive material layer (105 in Figs. 5a, 6a) are sequentially etched away to remove first and second regions of the switching and storage regions STrA and StgA and the first and second regions I and II. To fourth transparent conductive patterns 105a, 105b, 105c, and 105d and first to fourth buffer patterns 110a, 110b, 110c, and 110d and first to fourth amorphous silicon patterns 113a, 113b, and 113c thereon. , 113d), respectively. In this case, each pattern of the pixel electrode region PEA is connected to each of the patterns 105b, 110b, and 113b of the storage region StgA, and thus each pattern 105b and 110b of the storage region StgA is formed. , 113b).

As shown in Figs. 4A, 5C and 6C, ashing is performed to remove the second photoresist pattern (181b in Figs. 5B and 6B) having the second thickness (t2 in Figs. 5B and 6B). The second amorphous silicon pattern 113B in FIGS. 5B and 6B is exposed to correspond to the pixel electrode region PEA in the pixel region P. Referring to FIG.

Next, an exposed second amorphous silicon pattern (113b in FIGS. 5B and 6B) and a second buffer pattern (109b in FIGS. 5B and 6B) exposed in the pixel electrode region PEA in the pixel region P are disposed. The second transparent conductive pattern (105b of FIGS. 5B and 6B) is exposed by etching. In this case, the exposed second transparent conductive patterns 105b of FIGS. 5B and 6B form a pixel electrode 106, and a portion in which the pixel electrode 106 extends in the storage region StgC is a first storage electrode. 107 (first mask process).

Next, as shown in FIGS. 4B, 5D, and 6D, the first, second, third, and fourth amorphous silicon patterns formed in the switching and storage regions STrA and StgA and the first and second regions I and II. The first photoresist pattern (181a of FIGS. 5C and 6C) remaining on the upper portion of the first photoresist pattern (113A, 113B, 113C and 113D of FIGS. 5C and 6C) may be removed by ashing or stripping. 2, 3, 4 silicon patterns (113a, 113b, 113c, 113d in FIGS. 5C, 6C) are exposed.

Subsequently, an Excimer Laser Annealing (ELA) characterized by irradiating a laser beam having an appropriate energy density with respect to the exposed first to fourth amorphous silicon patterns (113a, 113b, 113c, and 113d of FIGS. 5C and 6C). Or by performing a sequential lateral solidification (SLS) process, the first, second, third, and fourth amorphous silicon patterns (113a, 113b, 113c, and 113d of FIGS. 5C and 6C) are melted, solidified, and recrystallized. First to fourth polysilicon patterns (not shown) are formed in each of (STrA, StgA) and the first and second regions (I, II).

The crystallization process may use a rapid thermal annealing (RTA) method in addition to the laser irradiation method.

In this case, the first, third, and fourth polysilicon patterns (not shown) in the switching region and the first and second regions STrA, I, and II may respectively include first, second, and third semiconductor layers 114, 118, and 120. The second polysilicon pattern 116 is formed between the second buffer pattern 110b and the first storage electrode 107 formed at a lower portion thereof, and a second storage electrode formed at an upper portion thereof through a subsequent process. In addition, a dielectric layer is formed.

Thereafter, an inorganic insulating material, for example, silicon oxide (SiO ₂ ) or silicon nitride (SiNx) is deposited on the entire surface of the first, second, and third semiconductor layers 114, 118, and 120 and the pixel electrode 106. 123 is formed.

In addition, a metal material of low resistance, for example, aluminum (Al), aluminum alloy (AlNd), copper (Cu), copper alloy, molybdenum (Mo), or chromium (Cr) on the gate insulating layer 123. The third photoresist pattern 183 is formed by forming a first metal layer (not shown) by depositing the photoresist layer, forming a photoresist layer (not shown) thereon, and exposing the same.

Subsequently, the first metal layer (not shown) exposed to the outside of the third photoresist pattern 183 is etched to etch the first and second regions in the switching region and the first and second regions STrA, I, and II. The first, second, and third gate electrodes 125, 129, and 131 are formed to correspond to the central portions of the three semiconductor layers 114, 118, and 120, respectively, and the first storage electrode 116 is formed in the storage region StgA. ) And a second storage electrode 127 overlapping with each other.

At the same time, the pixel portion PA is connected to the first gate electrode 125 and extends in one direction with the gate wiring 133 of FIG. 4B spaced apart from and parallel to the pixel line PA and connected to the second storage electrode 127. The common wiring (134 of FIG. 4B) is formed. At this time, substantially as a part of the common wiring (134 of FIG. 4B) itself forms the second storage electrode 127.

Thereafter, the third photoresist pattern and the first, second, and third gate electrodes 125, 129, and 131 disposed under the doping mask are doped with an n-type impurity having a first dose (piece / cm 2). As a result, first to third n-type ohmic contact layers 114b and 118b are exposed to regions of the first to third semiconductor layers 114, 118, and 120 exposed to both sides of the first to third gate electrodes 125, 129, and 131. , 120b), respectively. In this case, central portions of the first, second, and third semiconductor layers 114, 118, and 120 that are not doped by the first, second, and third gate electrodes 125, 129, and 131 may be formed of first, second, and third active layers 114a, respectively. 118a, 120a).

  Next, as shown in FIGS. 4B, 5E, and 6E, a third photoresist pattern remaining on the first to third gate electrodes 125, 129, and 131 by appropriately performing an isotropic ashing is performed. The thickness and width of the first and second gate electrodes 125, 129, and 131 below the first and third gate electrodes 125, 129, and 131 may be exposed by a predetermined width.

Thereafter, dry etching removes a predetermined width of both side portions of the first to third gate electrodes 125, 129, and 131 exposed to the outside of the third photoresist pattern 183 whose width is reduced. As a result, predetermined widths of the first to third active layers 114a, 118a, and 120a are exposed to the outside of the first to third gate electrodes 125, 129, and 131.

Thereafter, the first to third gate electrodes 125, 129, and 131 exposed to the outside of the first to third gate electrodes 125 to 131 by doping the second dose amount of the n-type impurity having a value smaller than the first dose amount are formed. The third active layer region forms the first to third LDD layers 114c, 118c, and 120c.

Therefore, the first to third semiconductor layers 114, 118, and 120 of the switching and first and second regions STrA, I, and II are all n-type ohmic contact layers 114b, 118b, and 120b and an LDD layer at this stage. (114c, 118c, 120c) and active layers 114a, 118a, 120a are included (second mask process).

Next, as illustrated in FIGS. 4B, 5F, and 6F, a third photoresist pattern remaining on the first to third gate electrodes 125, 129, and 131 and the second storage electrode 127 (FIG. 183 of 5e and 6e are removed by ashing or stripping, and a new photoresist is applied and exposed to light to develop the entire area of the first semiconductor layer 114 and the first region of the switching region STrA. A fourth photoresist pattern 185 is formed to cover the entire region of the second semiconductor layer 118 and the entire storage region StgA in the region I.

Thereafter, the third photoresist of the second region (II) is doped by doping a third dose amount of p-type impurities having a value greater than the first dose amount using the fourth photoresist pattern 185 as a doping mask. The third semiconductor layer 120 exposed to the outside of the gate electrode 131, that is, the third LDD layer (120c in FIGS. 5E and 6E) and the third n-type ohmic contact layer (120b in FIGS. 5E and 6E) are both p-type. An ohmic contact layer 120d is formed (third mask process).

This is due to the difference in the amount of dose to be doped. In the previous step (steps shown in FIGS. 5E and 6E), the n-type impurity having the first and second doses is already doped in the third semiconductor layer 120. To form a third n-type ohmic contact layer (120b in FIGS. 5E and 6E) and a third LDD layer (120c in FIGS. 5E and 6E), but a third dose larger than the first and second doses is provided in the region. Since the p-type impurity having doping becomes more doping (so that double doping of different types is called counter doping), the p-type ohmic contact layer 120d is used as an effect of the counter doping. Is converted to).

Therefore, by proceeding to the present step, the first semiconductor layer 114 having the first active layer 114a, the LDD layer 114c, and the n-type ohmic contact layer 114b is formed in the switching region STrA. In the first region I, a second semiconductor layer 118 having a second active layer 118a, an LDD layer 118c, and an n-type ohmic contact layer 118b is formed, and in the second region II, a second semiconductor layer 118 is formed. A third semiconductor layer 120 having three active layers 120a and a p-type ohmic contact layer 120d is formed.

Next, as shown in FIGS. 4C, 5G, and 6G, a fourth photoresist pattern (185 in FIGS. 5F and 6F) remaining in the switching region STrA, the storage region StgA, and the first region I is shown. Is removed by ashing or stripping.

Thereafter, an inorganic insulating material may be formed on the entire surface of the first to third gate electrodes 125, 129, and 131, the gate wiring 133 of FIG. 4C, the common wiring (134 of FIG. 4C), and the second storage electrode 127. For example, the protective layer 135 is formed by depositing silicon oxide (SiO ₂ ) or silicon nitride (SiNx) or by coating an organic insulating material such as benzocyclobutene (BCB) or photo acryl. Patterning exposes the first to fourth contact holes 140a, 140b, 142a, and 142b exposing the first and second n-type ohmic contact layers 114b and 118b, respectively, and the p-type ohmic contact layer 120d. To form fifth and sixth contact holes 144a and 144b.

In this case, one semiconductor layer is formed in each of the semiconductor layers 114, 118, and 120 because ohmic contact layers 114b, 118b, and 120b are formed on both sides of the active layers 114a, 118a, and 120a, respectively. Two contact holes 140a and 140b, 142a and 142b and 144a and 144b are formed corresponding to 114, 118 and 120, respectively.

In this case, a pixel electrode contact hole (145 in FIG. 4C) is formed to partially expose the pixel electrode 106 to correspond to the pixel electrode region PEA overlapping the drain electrode formed later (fourth mask process). .

Next, as shown in FIGS. 4D, 5H, and 6H, the first to sixth contact holes 140a, 140b, 142a, 142b, 144a, and 144b and the pixel electrode contact holes (145 of FIG. 4c) are provided. A second metal material is deposited on the layer 135 to form a second metal layer (not shown) by depositing a material selected from among copper (Cu), copper alloy, molybdenum (Mo), and chromium (Cr). Thereby contacting the first and second n-type ohmic contact layers 114b and 118b or the p-type ohmic contact layer 120d through the first to sixth contact holes 140a, 140b, 142a, 142b, 144a, and 144b, respectively. The first to third source electrodes 150a, 155a and 157a and the first to third drain electrodes 150b, 155b and 157b are formed to be spaced apart from each other. In this case, the first drain electrode 150b formed in the switching region STrA is formed to extend to the pixel electrode contact hole 145 of FIG. 4C, thereby exposing the pixel exposed through the pixel electrode contact hole 145 of FIG. 4C. It is also electrically connected to the electrode 106.

In addition, at the same time, a third storage electrode 153 overlapping with the second storage electrode 127 and connected to the first drain electrode 150b is formed to correspond to the storage area StgA.

In addition, a data line (160 in FIG. 4D) connected to the first source electrode 150a and intersecting the gate line (133 in FIG. 4D) is formed in the pixel part PA by the same process (fifth mask). Step) to complete the array substrate for the liquid crystal display device with integrated drive circuit according to the present invention.

The completed array of driving circuit integrated liquid crystal display devices according to the present invention overlaps each other in the storage area, and forms a storage capacitor having a double structure by forming first, second and third storage electrodes, thereby doubling the storage capacity. Let's go. Therefore, even if the area of the storage area is formed to have an area about half that of the prior art, it has a sufficient storage capacity, and the opening ratio can be improved.

As described above, the present invention provides a method of manufacturing an array substrate for a liquid crystal display device integrated with a driving circuit unit by performing a total of five mask processes, thereby reducing manufacturing time and cost through process simplification, and improving productivity and yield.

In addition, the storage capacitor is formed to have a double-layer structure to increase the storage capacity per unit area, thereby ensuring sufficient storage capacity even if the storage area is reduced, thereby improving the aperture ratio.

Claims (20)

Forming a first to fourth amorphous silicon pattern and a transparent conductive pattern under the transparent conductive pattern, a pixel electrode made of the same material on the same layer as the transparent conductive pattern, and a first storage electrode connected to the pixel electrode on the substrate Wow; Crystallizing the first to third amorphous silicon patterns to form first to third semiconductor layers of polysilicon; Forming a gate insulating film over the first to third semiconductor layers and the first storage electrode and the pixel electrode; Forming first to third gate electrodes on each of central portions of the first to third semiconductor layers above the gate insulating layer, and simultaneously forming second storage electrodes to correspond to the first storage electrodes; A first dose of n + doping, a second dose of n + doping and a third dose of p + doping to form an active layer that is not doped in each of the first and second semiconductor layers, and an n + doped n-type ohmic Forming a contact layer, an n− doped LDD layer, and forming an undoped active layer and a p + doped p-type ohmic contact layer on the third semiconductor layer; Forming first to third source and drain electrodes that are in contact with and spaced apart from the ohmic contact layers of the first to third semiconductor layers, respectively, and are simultaneously connected to the first drain electrode and corresponding to the second storage electrode, respectively. Forming storage electrodes Method of manufacturing an array substrate for a drive circuit-integrated liquid crystal display device comprising a. The method of claim 1, Forming a first to fourth amorphous silicon pattern and a transparent conductive pattern under the transparent conductive pattern, a pixel electrode made of the same material on the same layer as the transparent conductive pattern, and a first storage electrode connected to the pixel electrode on the substrate Is, Sequentially forming a transparent conductive material layer, a first buffer layer, and an amorphous silicon layer on the substrate; Forming a first photoresist pattern of a first thickness and a second photoresist pattern of a second thickness thinner than the first thickness over the amorphous silicon layer; Removing the amorphous silicon layer, the first buffer layer, and the transparent conductive material layer exposed to the outside of the first and second photoresist patterns to form first to fourth patterns having a triple layer structure; Removing the second photoresist pattern to expose a portion of the fourth pattern; Forming the pixel electrode of a transparent conductive material by removing an amorphous silicon pattern and a buffer pattern which form an uppermost layer and an intermediate layer among the exposed fourth patterns; Exposing the first to third amorphous silicon patterns forming the uppermost layer of the first to third patterns by removing the first photoresist pattern. Method of manufacturing an array substrate for a drive circuit-integrated liquid crystal display device comprising a. The method of claim 2, Forming the first photoresist pattern having the first thickness and the second photoresist pattern having the second thickness may include: Forming a photoresist layer over the amorphous silicon layer; Exposing the photoresist layer using an exposure mask having a light blocking region, a transmissive region, and a transflective region; Developing the exposed photoresist layer Method of manufacturing an array substrate for a drive circuit-integrated liquid crystal display device comprising a. The method of claim 1, The crystallization is a method of manufacturing an array substrate for a liquid crystal display device with a drive circuit, characterized in that for irradiating a laser to melt the first to fourth amorphous silicon pattern. The method of claim 1, A first dose of n + doping, a second dose of n + doping and a third dose of p + doping to form an active layer that is not doped in each of the first and second semiconductor layers, and an n + doped n-type ohmic Forming a contact layer, an n− doped LDD layer, and forming an undoped active layer and a p + doped p-type ohmic contact layer on the third semiconductor layer, Doping a first dose of n-type impurities using the first to third gate electrodes as a doping mask to form first to third n-type ohmic contact layers on both sides of the first to third semiconductor layers, respectively, Making the undoped portions corresponding to the first to third gate electrodes to form the first to third active layers; Performing dry etching to remove predetermined widths of both sides of the first to third gate electrodes; Forming first to third LDD layers by doping n-type impurities having a second dose smaller than the first dose to the first to third actin layers exposed to the outside of the first to third gate electrodes. Wow; A photoresist pattern is formed on the first and second gate electrodes and the second storage electrode to cover the first and second semiconductor layers and the second storage electrode, and a third dose greater than the first dose is formed. Forming the third LDD layer and the third n-type ohmic contact layer formed on the third semiconductor layer as a p-type ohmic contact layer by doping the p-type impurity; Removing the photoresist pattern Method of manufacturing an array substrate for a drive circuit-integrated liquid crystal display device comprising a. The method of claim 1, Forming the first to third source and drain electrodes and the third storage electrode, which are in contact with and spaced apart from each other in the ohmic contact layer of the first to third semiconductor layers, Forming a protective layer having first to sixth contact holes exposing the first to second n-type ohmic contact layer and the p-type ohmic contact layer, respectively, on the first to third gate electrodes and the second storage electrode; Steps; First to third source electrodes and first to third drains contacting and spaced apart from the first to second n-type ohmic contact layer and the p-type ohmic contact layer through the first to sixth contact holes on the protective layer; Forming an electrode Method of manufacturing an array substrate for a drive circuit-integrated liquid crystal display device comprising a. The method of claim 1, Forming the protective layer having the first to sixth contact holes, And forming a pixel electrode contact hole exposing the pixel electrode. The method of claim 7, wherein Forming the first to third source and drain electrodes And allowing the first drain electrode to be electrically connected to the pixel electrode through the pixel electrode contact hole. The method of claim 1, Before forming the first to fourth amorphous silicon patterns and the pixel electrode on the substrate Forming a second buffer layer on the substrate Method of manufacturing an array substrate for a drive circuit-integrated liquid crystal display device further comprising. The method of claim 1, Forming the first to third gate electrodes, Forming a gate line connected to the first gate electrode and extending in one direction Method of manufacturing an array substrate for a drive circuit-integrated liquid crystal display device further comprising. The method of claim 10, Forming the gate wiring, Forming a common wiring connected to the second storage electrode and extending in parallel with the gate wiring; Method of manufacturing an array substrate for a drive circuit-integrated liquid crystal display device further comprising. The method of claim 10, Forming the first to third source and drain electrodes and a third storage electrode may include: Forming a data line connected to the first drain electrode and crossing the gate line; Method of manufacturing an array substrate for a drive circuit-integrated liquid crystal display device further comprising. A pixel electrode and a first storage electrode formed of the first to fourth transparent conductive patterns and the same material formed on the substrate; First to fourth buffer patterns respectively formed on the first to fourth transparent conductive patterns; A semiconductor pattern formed on the first to third semiconductor layers and the fourth buffer pattern formed on the first to third buffer patterns; A gate insulating film formed over the first to third semiconductor layers and the pixel electrode; First to third gate electrodes formed on a central portion of the first to third semiconductor layers and corresponding to the first storage electrodes on the gate insulating layer; First to sixth contact holes formed on an entire surface of the first to third gate electrodes and the second storage electrodes, and exposing first to third semiconductor layers on both sides of the first to third gate electrodes; A protective layer formed; First to third source and drain electrodes formed to be in contact with the first to third semiconductor layers and spaced apart from each other through the first to sixth contact holes; A third storage electrode formed on the same layer as the first to third source and drain electrodes to correspond to the second storage electrode Drive circuit-integrated liquid crystal display device array substrate comprising a. The method of claim 13, And the third storage electrode is connected to the first drain electrode. The method of claim 13, The protective layer further includes a pixel electrode contact hole exposing a portion of the pixel electrode. The method of claim 15, And the first drain electrode is in contact with the pixel electrode through the pixel electrode contact hole. The method of claim 13, On the gate insulating film, A gate wiring connected to the first gate electrode and extending in one direction; A common wiring spaced apart from the gate wiring and connected to the second storage electrode The further formed drive circuit integrated liquid crystal display device array substrate. The method of claim 17, On the protective layer, And a driving circuit integrated with the first source electrode and having a data line crossing the gate line. The method of claim 13, The first and second semiconductor layers, Corresponding to portions corresponding to the first and second gate electrodes, undoped first and second active layers, and low concentration n-doped first and second LDD layers on both sides of the first and second active layers, respectively. And a high concentration n + doped first and second n-type ohmic contact layers on the outside of each of the first and second LDD layers. The method of claim 19, The third semiconductor layer, An array substrate for a drive circuit-integrated liquid crystal display device comprising a third active layer undoped corresponding to the portion corresponding to the third gate electrode, and a p + doped p-type ohmic contact layer at both sides of the third active layer. .

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