KR20020095997A - Fabricating method of liquid crystal display - Google Patents

Abstract

PURPOSE: A method for fabricating a liquid crystal display device is provided to carry out the photolithography by using three masks, thereby reducing the required masks and simplifying the fabricating steps, increasing the yield. CONSTITUTION: A method for fabricating a liquid crystal display device includes the steps of forming gate patterns(42) by carrying out photolithography via a first mask on channel areas, storage areas and gate pad parts of a glass substrate, stacking a gate insulating film(43), an active layer(44) and an electrode layer(45) on the substrate, forming a photoresist pattern on the electrode layer, and exposing and developing the photoresist film via a second mask for forming photoresist patterns remaining on the channel areas, the storage areas and data pad parts, the thickness of the photoresist pattern being thin on the electrode layer of the gate pattern on the channel areas by exposure, etching the photoresist pattern to expose the gate insulating film and etching the gate insulating film by a predetermined thickness, removing the exposed portions of the photoresist film and defining source/drain areas(46,47) by etching the exposed electrode layer simultaneously with removing the exposed gate insulating film, forming pixel electrodes(48) via a third mask for connecting the drain areas with the electrode layer on the storage areas and forming first and second wires(49,50) respectively connected to the gate pattern of the gate pads and the electrode layer on the data pads, and etching the exposed active layer of the active areas by a predetermined thickness.

Description

Manufacturing method of liquid crystal display device {FABRICATING METHOD OF LIQUID CRYSTAL DISPLAY}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a liquid crystal display, and more particularly, to a method for manufacturing a liquid crystal display that is suitable for minimizing the number of masks required for manufacturing a liquid crystal display.

Referring to the procedure cross-sectional view of Figures 1a to 1e attached to the conventional method of manufacturing a liquid crystal display as follows.

First, as shown in FIG. 1A, a gate electrode material is formed on an upper portion of the glass substrate 1, and then photolithography is performed through a first mask (not shown). A gate pattern 2 is selectively formed on the channel region, the storage region and the gate pad portion.

As shown in FIG. 1B, a gate insulating film 3 and an active layer 4 having a SiNx material are sequentially formed on the resultant, and then photolithography is performed through a second mask (not shown). Is selectively etched such that the active layer 4 remains on the channel region. At this time, the active layer 4 is formed by laminating amorphous silicon and a high concentration of (N) doped amorphous silicon.

As shown in FIG. 1C, a source / drain electrode material is formed on the resultant, and then photolithography is performed through a third mask (not shown) to form the source / drain electrode material in the channel region. Etching may be applied to the source / drain regions 5 and 6 spaced apart from both sides of the active layer 4, and applied to the electrode 7 remaining on the gate insulating layer 3 on the storage region. Etching is applied to the storage capacitor through the gate insulating film 3 together with the lower gate pattern 2 and selectively etched to be applied to the electrode 8 remaining on the gate insulating film 3 of the data pad part.

Then, as shown in FIG. 1D, the passivation layer 9 is formed on the resultant, and then photolithography is performed through a fourth mask (not shown) to store the drain region 6 of the channel region. The electrode 7 of the region, the gate pattern 2 of the gate pad portion, and the electrode 8 of the data pad portion are selectively etched to expose the electrode 7.

In addition, as shown in FIG. 1E, an electrode material is formed on the resultant, and then photolithography is performed through a fifth mask (not shown) to form the drain region 6 of the channel region and the storage region. The pixel electrode 10 for connecting the electrode 7 is formed, and the wiring 11 connected to the gate pattern 2 of the gate pad part and the wiring 12 connected to the electrode 8 of the data pad part are simultaneously formed. Etch selectively to do so.

As described above, the conventional method of manufacturing the liquid crystal display device has a problem in that it reduces the manufacturing cost and simplifies the process by applying photolithography using five masks.

Thus, a method of manufacturing a liquid crystal display device in which four masks are applied is proposed. Referring to the procedure cross-sectional view of Figures 2a to 2g attached to the conventional method of manufacturing a liquid crystal display device applying the four masks as follows.

First, as shown in FIG. 2A, an electrode material is formed on an upper portion of the glass substrate 21, and then photolithography is performed through a first mask (not shown) to store the channel region of the glass substrate 21. The gate pattern 22 is selectively formed on the region and the gate pad portion.

As shown in FIG. 2B, a gate insulating film 23 made of SiNx material, an active layer 24, and an electrode layer 25 made of an electrode material are sequentially formed on the resultant. In this case, the active layer 24 stacks amorphous silicon and a high concentration of undoped amorphous silicon.

As shown in FIG. 2C, the photoresist film PR21 is formed on the electrode layer 25, and then photolithography is performed through a second mask (not shown) to form the channel region, the storage region, and the data. A pattern of the photoresist film PR21 remaining selectively on the pad part is formed, but diffraction exposure is applied to the photoresist film PR21 on the electrode layer 25 on the channel region gate pattern 22 to form a photoresist film PR21 in another region. The film is thinner than the pattern, and then the laminated film in the exposed region is etched through the pattern of the photosensitive film PR21 until the gate insulating film 23 is exposed.

As shown in FIG. 2D, the diffraction exposure is applied to selectively remove the upper photoresist film PR21 on the electrode layer 25 on the channel region gate pattern 22 having a thickness thinner than that of the photoresist film PR21 pattern of another region. do.

As shown in FIG. 2E, the photoresist film PR21 pattern is selectively removed to etch the exposed electrode layer 25, and then the active layer 24 is etched by a predetermined thickness to remove the active layer 24. Source / drain regions 26 and 27 spaced apart from each other are formed on both sides, and the remaining pattern of the photoresist film PR21 is removed.

As shown in FIG. 2F, a protective film 28 of SiNx material is formed on the upper surface of the resultant, and then photolithography is performed through a third mask (not shown) to form a drain region of the channel region. 27), the electrode layer 25 of the storage region, the gate pattern 22 of the gate pad portion, and the electrode layer 25 of the data pad portion are selectively etched to expose the electrode layer 25.

As shown in FIG. 2G, an electrode material is formed on the resultant, and then photolithography is performed through a fourth mask (not shown) to form the drain region 27 and the storage region of the channel region. The pixel electrode 29 connecting the electrode layer 25 is formed, and the wiring 30 connected to the gate pattern 22 of the gate pad part and the wiring 31 connected to the electrode layer 25 of the data pad part are simultaneously formed. Etch selectively to do so.

The manufacturing method of the liquid crystal display device in which photolithography is applied by applying the four masks as described above can reduce the manufacturing cost and simplify the process compared to applying the five masks.

That is, minimizing the number of masks used may contribute to manufacturing cost reduction and process simplicity.

Accordingly, an object of the present invention is to provide a method of manufacturing a liquid crystal display device which can manufacture a liquid crystal display device using three masks.

1A to 1E are cross-sectional views showing a manufacturing method of a liquid crystal display device employing five masks in the related art.

2A to 2G are cross-sectional views showing a manufacturing method of a liquid crystal display device employing four masks in the related art.

3A to 3G are cross-sectional views showing an example of a method of manufacturing a liquid crystal display device employing three masks according to the present invention.

FIG. 4 is an exemplary view showing subsequent protective film formation in FIG. 3G. FIG.

** Explanation of symbols for main parts of drawings **

41: glass substrate 42: gate pattern

43: gate insulating film 44: active layer

44A: Amorphous Silicon 44B: High Concentration End Doping Amorphous Silicon

45 electrode layer 46 source region

47: drain region 48: pixel electrode

49, 50: wiring 51: protective film

According to an aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device, including forming a gate pattern by performing photolithography on a channel region, a storage region, and a gate pad portion of a glass substrate through a first mask; ; Stacking a gate insulating film, an active layer and an electrode layer on top of the resultant material; A photoresist layer is formed on the electrode layer and exposed and developed through a second mask to form a photoresist pattern remaining on the channel region, the storage region, and the data pad portion of the glass substrate, but diffracted on the electrode layer on the channel region gate pattern. Applying an exposure to form a thin photosensitive film; Etching the laminated film exposed through the photosensitive film pattern until the gate insulating film is exposed, and subsequently etching the gate insulating film to a predetermined thickness; Removing a region to which diffraction exposure is applied to the photoresist layer, and etching the exposed electrode layer to define a source / drain region and to remove the exposed gate insulating layer; After removing the photoresist pattern, a conductive material is formed, and photolithography is performed through a third mask to form a pixel electrode connecting the electrode layer of the drain region and the storage region. Forming a second wiring connected to the electrode layer of the wiring and the data pad portion; And etching the active layer exposed to the channel region to a predetermined thickness.

Referring to FIG. 3A to FIG. 3G, which are attached to the manufacturing method of the liquid crystal display device according to the present invention as described above, an embodiment is described in detail as follows.

First, as shown in FIG. 3A, a conductive material such as Cr, MoW, Cr / Al, Cu, Al (Nd), or Cr / Al (Nd) is formed on the glass substrate 41, and then the first mask ( Photolithography is performed on the channel to selectively form the gate pattern 42 on the channel region, the storage region, and the gate pad portion.

As shown in FIG. 3B, an electrode layer 45 made of a SiNx gate insulating film 43, an active layer 44, and a conductive material such as Mo, Cr, Al, or Al (Nd) is formed on top of the resultant product. After forming sequentially, the photoresist film PR41 is formed on the electrode layer 45, and photolithography is performed through a second mask (not shown) to selectively select the channel region, the storage region, and the data pad portion. A pattern of the remaining photoresist film PR41 is formed, but diffraction exposure is performed on the electrode layer 45 on the channel region gate pattern 42 so that the photoresist film PR41 has a thinner thickness than other regions. In this case, the active layer 44 is preferably formed such that amorphous silicon 44A and high concentration of the undoped amorphous silicon 44B are stacked.

As shown in FIG. 3C, the stacked layer of the region exposed through the pattern of the photosensitive film PR41 is etched until the gate insulating film 43 is exposed, and then the gate insulating film 43 is etched to a predetermined thickness. . In this case, the gate insulating layer 43 may be etched by a thickness appropriately considered so that the gate insulating layer 43 may be completely removed at the same time as the subsequent channel region electrode layer 45 is etched.

As shown in FIG. 3D, the diffraction exposure is applied to selectively remove the upper photoresist film PR41 on the electrode layer 45 on the channel region having a thickness thinner than that of other regions.

As shown in FIG. 3E, the pattern of the photoresist film PR41 is selectively removed to etch the exposed electrode layer 45 so that the source / drain regions 46 and 47 are spaced apart on both sides of the active layer 44. ) And the gate insulating film 43 etched to the predetermined thickness is completely etched. In this case, the exposed gate insulating layer 43 may be simultaneously etched while the electrode layer 45 is dry etched, and the gate insulating layer 43 of SiNx may be easily etched when the electrode layer 45 is made of Mo.

As shown in FIG. 3F, the photoresist layer PR41 pattern is removed, and then a conductive material is formed on the upper surface, and photolithography is performed through a third mask (not shown) to drain the channel region. A pixel electrode 48 connecting the 47 and the electrode layer 45 of the storage region is formed, and at the same time, the wiring 49 connected to the gate pattern 42 of the gate pad portion and the electrode layer 45 of the data pad portion are connected. It is selectively etched to form the wiring 50 at the same time. At this time, if the conductive material applied to the pixel electrode 48 and the wirings 49 and 50 is formed of indium tin oxide (ITO), and dry etching is performed, it is possible to prevent damage to the metal exposed on the channel region or other regions. Can be.

As shown in FIG. 3G, the high concentration of the undoped amorphous silicon 44B is etched from the active layer 44 exposed to the channel region, followed by etching the amorphous silicon 44A to a predetermined thickness.

On the other hand, as shown in FIG. 4, the channel region is applied to the passivation layer 51 on the channel region and the storage region, for example, by applying a black matrix (BM on array), a color filter, or a PI alignment layer. It is desirable to protect.

The method of manufacturing a liquid crystal display device according to the present invention as described above can produce a liquid crystal display device by performing photolithography through three masks, thereby minimizing the number of masks used, contributing to a reduction in manufacturing cost and a simplified process. Thereby, there exists an effect which can improve a yield.

Claims (4)

Forming a gate pattern by performing photolithography on the channel region, the storage region and the gate pad portion of the glass substrate through a first mask; Stacking a gate insulating film, an active layer and an electrode layer on top of the resultant material; A photoresist layer is formed on the electrode layer and exposed and developed through a second mask to form a photoresist pattern remaining on the channel region, the storage region, and the data pad portion of the glass substrate, but diffracted on the electrode layer on the channel region gate pattern. Applying an exposure to form a thin photosensitive film; Etching the laminated film exposed through the photosensitive film pattern until the gate insulating film is exposed, and subsequently etching the gate insulating film to a predetermined thickness; Removing a region to which diffraction exposure is applied to the photoresist layer, and etching the exposed electrode layer to define a source / drain region and to remove the exposed gate insulating layer; After removing the photoresist pattern, a conductive material is formed, and photolithography is performed through a third mask to form a pixel electrode connecting the electrode layer of the drain region and the storage region. Forming a second wiring connected to the electrode layer of the wiring and the data pad portion; And etching the active layer exposed to the channel region to a predetermined thickness. The method of claim 1, wherein the active layer is formed by stacking amorphous silicon and a high concentration of undoped amorphous silicon. 2. The gate of claim 1, wherein the gate insulating layer is formed of SiNx material, and the electrode layer is formed of Mo material to etch the electrode layer to define source / drain regions spaced apart on both sides of the active layer. A method of manufacturing a liquid crystal display device comprising etching an insulating film. The liquid crystal display of claim 1, wherein a black matrix, a color filter, or a PI alignment layer is applied as a passivation layer on the channel region and the storage region through a subsequent process. Way.