TWI450006B - Method for fabricating and repairing pixel structure and repaired pixel structure - Google Patents

Description

Pseudo element structure manufacturing method and repairing method and repaired pixel structure

The present invention relates to a repairing method, a repaired structure, and a method for fabricating a pixel structure, and particularly relates to a repair method of a pixel structure, a repaired pixel structure, and a pixel using a less photomask. The method of making the structure.

The liquid crystal display is mainly composed of a thin film transistor array substrate, a color filter array substrate and a liquid crystal layer, wherein the thin film transistor array substrate is composed of a plurality of arrayed pixel structures. In general, the method of fabricating the pixel structure includes the following steps. First, a gate is formed on a substrate. Next, a gate insulating layer is formed on the substrate to cover the gate. Then, a semiconductor channel layer is formed on the gate insulating layer. Thereafter, a source and a drain are formed over the semiconductor channel layer. Next, a protective layer is formed on the substrate to cover the semiconductor channel layer, the source, and the drain. Then, a contact window is made on the protective layer. Thereafter, a pixel electrode is formed on the protective layer, and the pixel electrode is partially filled in the contact window to be electrically connected to the drain. In this way, the production of the pixel structure is roughly completed.

As described above, the conventional pixel structure is mainly formed by forming a gate by a first mask, a second mask forming a semiconductor channel layer, a third mask forming a source and a drain, and a fourth mask forming a contact window. And the fifth mask forms a pixel electrode. Therefore, the fabrication of the conventional pixel structure is a process using a five-mask, so that the production steps are more and the production time is longer. When the production steps are complicated, the pixel structure has a higher chance of producing defects and a lower production yield. However, with the development trend of thin film transistor liquid crystal displays toward large-scale fabrication, the fabrication of thin film transistor array substrates will face many problems and challenges, such as yield reduction and capacity reduction. Wait. Therefore, if the number of masks capable of reducing the pixel structure is reduced, that is, the number of exposure processes for fabricating the thin film transistor component is reduced, the manufacturing time can be reduced, the throughput can be increased, the manufacturing cost can be reduced, and the yield can be improved.

Various methods have been proposed in the industry to reduce the number of masks. One way is to use a half tone mask (HTM) or a gray tone mask (GTM) to reduce the number of masks. This method is mainly used as a half-tone or gray-tone mask as two masks. After half-tone exposure and development, the gate region is etched, and then the source and drain regions are further etched. However, when a half-tone or gray-tone mask is used, it is difficult to control the optical exposure of the photoresist, and thus the pixel structure produced is liable to have a short circuit or a dot defect. However, if these defective liquid crystal display panels are directly discarded, the manufacturing cost will be greatly increased. In general, it is very difficult to rely solely on improved process technology to achieve zero defect rate, so the patching technique of the pixel structure becomes quite important.

The invention provides a repairing method for a pixel structure for repairing a defective pixel structure to improve product yield.

The present invention provides a repaired pixel structure which is a pixel structure formed by the above-described repairing method.

The invention provides a method for fabricating a pixel structure, which can reduce the number of masks used and has better product reliability.

The present invention proposes a repair method for a pixel structure suitable for repairing a pixel structure. The pixel structure is disposed on a substrate, and the pixel structure includes an active component, a protective layer, and a pixel electrode. The active device includes a gate, a gate insulating layer, a semiconductor layer, and a metal layer. The gate is disposed on the substrate. Brake insulation Located between the semiconductor layer and the gate. The semiconductor layer has a channel region and an opening exposing a portion of the gate insulating layer. The metal layer has a first drain block, a second drain block, and a source block. The source block and the second drain block are located on both sides of the channel area. The source block is located between the first drain block and the second drain block. The source block and the first drain block are located on both sides of the opening. The protective layer covers the active component and is in direct contact with a portion of the gate insulating layer exposed by the opening. The protective layer has a first contact window. The pixel electrode is disposed on the protective layer and electrically connected to the first drain block through the first contact window. The repairing method includes: forming a second contact window penetrating the pixel electrode and the protective layer, wherein the second contact window exposes a portion of the second drain block; and forming a conductive layer in the second contact window, and the pixel electrode is transparent The conductive layer is electrically connected to the second drain block.

In an embodiment of the invention, the method of forming the second contact window comprises a laser ablation process.

In an embodiment of the invention, the method for forming a conductive layer comprises a local chemical vapor deposition (CVD) film formation method.

In an embodiment of the invention, the material of the conductive layer comprises tungsten.

In one embodiment of the invention, the method of forming a conductive layer includes fusing a second drain block through a fusing step.

In one embodiment of the invention, the fusing step includes a laser welding process.

The invention also provides a repaired pixel structure comprising an active component, a protective layer, a pixel electrode and a conductive layer. The active component is disposed on a substrate and includes a gate, a gate insulating layer, a semiconductor layer, and a metal layer. The gate is located on the substrate. The gate insulating layer is disposed on the substrate and covers the gate. The semiconductor layer is disposed on the gate insulating layer and has a channel region and an opening exposing a portion of the gate insulating layer. The metal layer is disposed on the semiconductor layer and has a first layer a pole block, a second bungee block, and a source block. The source block and the second drain block are located on both sides of the channel area. The source block is located between the first drain block and the second drain block, and the source block and the first drain block are located on both sides of the opening. The protective layer covers the active component and is in direct contact with a portion of the gate insulating layer exposed by the opening. The protective layer has a first contact window. The pixel electrode is disposed on the protective layer and has a second contact window penetrating the pixel electrode and the protective layer. The pixel electrode is electrically connected to the first drain block through the first contact window, and the second contact window exposes a portion of the second drain block. The conductive layer is disposed in the second contact window, and the pixel electrode is electrically connected to the second drain block through the conductive layer.

In an embodiment of the invention, the material of the conductive layer comprises tungsten.

In an embodiment of the invention, the material of the conductive layer is substantially the same as the material of the second drain block.

The invention further provides a method for fabricating a pixel structure, which comprises the following steps. A gate, a gate insulating layer, a semiconductor layer and a metal layer are sequentially formed on a substrate. A photoresist layer is formed on the metal layer. The photoresist layer is exposed by a gray scale mask, wherein the gray scale mask has a light transmitting region, a half light transmitting region and a light shielding region, wherein the light transmitting region is located between the semi-light transmitting region and the light shielding region. The exposed photoresist layer is developed to form a patterned photoresist layer, wherein the patterned photoresist layer has a via exposing a portion of the metal layer and a blind via. The patterned photoresist layer is an etch mask, and a portion of the metal layer exposed by the via and a portion of the semiconductor layer underneath the via are removed, and the removed portion corresponds to a metal layer under the blind via and a portion of the semiconductor layer underneath And forming an opening and a channel region exposing a portion of the gate insulating layer on the semiconductor layer, and dividing the metal layer into a first drain block, a second drain block, and a source block. The source block and the second drain block are located on both sides of the channel area. The source block is located between the first drain block and the second drain block, and the source block and the first drain block are located on both sides of the opening. Remove Patterned photoresist layer. Forming a protective layer on the substrate, wherein the protective layer has a first contact window, and the protective layer covers the metal layer and is in direct contact with the portion of the gate insulating layer that is opened. A pixel electrode is formed on the protective layer, wherein the pixel electrode is electrically connected to the first drain block through the first contact window. A second contact window is formed through the pixel electrode and the protective layer, wherein the second contact window exposes a portion of the second drain block. A conductive layer is formed in the second contact window, and the pixel electrode is electrically connected to the second drain block through the conductive layer.

Based on the above, since the present invention uses a gray scale mask to fabricate a metal layer having a first drain block, a second drain block, and a source block, the semiconductor layer is exposed when the photoresist is overexposed. When the opening of the insulating layer is opened, and the first drain block loses its function, the pixel structure can be repaired by forming a second contact window to electrically connect the conductive layer to the pixel electrode and the second drain block. . In this way, the pixel structure that needs to be scrapped can be repaired and reused. Therefore, the repair method of the pixel structure of the present invention can improve the yield of production and reduce the overall manufacturing cost, and the repaired pixel structure has better reliability.

The above described features and advantages of the present invention will be more apparent from the following description.

1A to 1K are schematic cross-sectional views showing a method of fabricating a pixel structure according to an embodiment of the present invention. Referring to FIG. 1A first, the method for fabricating the pixel structure of the embodiment includes the following steps. First, a gate 112, a gate insulating layer 114, a semiconductor layer 116, and a metal layer 118 are sequentially formed on a substrate 10. The substrate 10 is, for example, a glass substrate, a flexible substrate, or a substrate of another suitable material.

The method of forming the gate 112 is, for example, first depositing a conductive layer (not shown), and then patterning the conductive layer by lithography and an etch process to form the gate 112. The material of the gate insulating layer 114 is, for example, tantalum oxide or tantalum nitride or a laminate thereof, and the method of forming the gate insulating layer 114 is, for example, chemical vapor deposition (CVD). The material of the semiconductor layer 116 is, for example, amorphous germanium or polycrystalline germanium. The gate 112 and the metal layer 118 are generally made of a metal material based on conductivity considerations. However, the present invention is not limited thereto. In other embodiments, the gate 112 and the metal layer 118 may also use other conductive materials, such as alloys, nitrides of metal materials, oxides of metal materials, and oxynitrides of metal materials. Or a stack of metallic materials and other conductive materials.

Next, referring again to FIG. 1A, a photoresist layer 20 is formed on the metal layer 118, wherein the photoresist layer 20 covers a portion of the metal layer 118.

Next, referring to FIG. 1B, the photoresist layer 20 is exposed by a gray scale mask 30. The gray scale mask 30 has a light transmitting region 32, a half light transmitting region 34, and a light shielding region 36, wherein the light transmitting region 32 is located between the semi-transmissive region 34 and the light-shielding region 36.

Next, referring back to FIG. 1B, the exposed photoresist layer 20 is developed to form a patterned photoresist layer 20a, wherein overexposure is caused due to the difference in fabrication, thereby causing the patterned photoresist layer 20a to have a A portion 22 of the portion of the metal layer 118 and a blind hole 24 are exposed. Among them, the normal exposure value is from 46 mJ/cm 2 to 54 mJ/cm 2 , and the abnormal exposure exposure value is between 54 mJ/cm 2 and 62 mJ/cm 2 .

Next, referring to FIG. 1C and FIG. 1D in sequence, the photoresist layer 20a is patterned as an etching mask, and a portion of the metal layer 118 exposed by the via 22 and a portion of the semiconductor layer 116 under the via 22 are removed. An opening S exposing a portion of the gate insulating layer 114 is formed on the layer 116. Here, the opening S is a broken circuit (open Defect). Further, a method of removing a portion of the metal layer 118 exposed by the via 22 and a portion of the semiconductor layer 116 thereunder is, for example, an etching process.

Next, referring to FIG. 1E and FIG. 1F in sequence, the photoresist layer 20a is patterned as an etching mask, and a portion of the semiconductor layer 116 corresponding to the underside of the blind via 24 and a portion of the semiconductor layer 116 underneath the blind via 24 are removed. A channel region 116a is formed on layer 116. The method of removing the portion corresponding to the metal layer 118 under the blind via 24 and the portion of the semiconductor layer 116 under it is, for example, an etching process. At this time, the etching process divides the metal layer 118 into a first drain block 118a, a second drain block 118b, and a source block 118c. The source block 118c and the second drain block 118b are located on both sides of the channel region 116a, and the source block 118c is located between the first drain block 118a and the second drain block 118b, and The source block 118c and the first drain block 118a are located on both sides of the opening S.

Next, referring to FIG. 1G, the patterned photoresist layer 20a is removed to expose the first drain block 118a, the second drain block 118b, and the source block 118c.

Then, referring to FIG. 1H, a protective layer 120 is formed on the substrate 10, wherein the protective layer 120 has a first contact window C1, and the protective layer 120 covers the metal layer 118 and is in direct contact with a portion of the gate insulating layer 114 of the opening S. .

Then, referring to FIG. 1I, a pixel electrode 130 is formed on the protective layer 120, wherein the pixel electrode 130 is electrically connected to the first drain block 118a through the first contact window C1. So far, the fabrication of the pixel structure 100 has been substantially completed.

Since the photoresist layer 20 of the present embodiment is caused by overexposure, the semiconductor layer 140 generates an open defect, which means that the opening 116a of the portion of the gate insulating layer 114 is exposed. As a result, the pixel structure 100 will produce a bright spot due to the opening S. With respect to the above-described circuit breaker, it will be explained below how to repair the pixel structure 100 having the circuit breaker by using the repairing method of the present invention.

Next, referring to FIG. 1J, a second contact window C2 is formed through the pixel electrode 130 and the protective layer 120, wherein the second contact window C2 exposes a portion of the second drain block 118b. In the present embodiment, the method of forming the second contact window C1 is, for example, a laser cutting process.

Finally, referring to FIG. 1K, a conductive layer 140 is formed in the second contact window C2, wherein the pixel electrode 130 is electrically connected to the second drain block 118b through the conductive layer 140. In the present embodiment, the material of the conductive layer 140 is, for example, tungsten, and a method of forming the conductive layer 140 is a local chemical vapor deposition (CVD) film formation method. It should be noted that the present invention does not limit the method of forming the conductive layer 140 and the second contact window C2. In other embodiments, the method of forming the conductive layer 140 and the second contact window C2 may also be through a laser welding process. (laser welding) to simultaneously form the second contact window C2 and the welded portion second drain block 118b as the conductive layer 140. That is to say, in other embodiments, the material of the conductive layer 140 is substantially the same as the material of the second drain block 118b. So far, the repair of the pixel structure 100 having the broken circuit has been completed, and a repaired pixel structure 100a is formed.

Structurally, referring again to FIG. 1K, the repaired pixel structure 100a includes a gate 112, a gate insulating layer 114, a semiconductor layer 116, a metal layer 118, a protective layer 120, a pixel electrode 130, and a conductive layer 140, wherein the gate electrode The gate insulating layer 114 , the semiconductor layer 116 , and the metal layer 118 form an active device 110 , and the active device 110 is disposed on the substrate 10 . In detail, the gate 112 is located on the substrate 10, and the gate insulating layer 114 is disposed on the substrate 10 and covers the gate 112. The semiconductor layer 116 is disposed on the gate insulating layer 114 and has a via region 116a and an opening S exposing a portion of the gate insulating layer 114. The metal layer 118 is disposed on the semiconductor layer 116 and has a first drain block 118a, a second drain block 118b, and a source block 118c. The source block 118c is located at the second drain block 118b On both sides of the channel area 116a. The source block 118c is located between the first drain block 118a and the second drain block 118b, and the source block 118c and the first drain block 118a are located on both sides of the opening S. The protective layer 120 covers the active device 110 and is in direct contact with a portion of the gate insulating layer 114 exposed by the opening S, wherein the protective layer 120 has a first contact window C1. The pixel electrode 130 is disposed on the protective layer 120 and has a second contact window C2 penetrating the pixel electrode 130 and the protective layer 120. The pixel electrode 130 is electrically connected to the first drain block 118a through the first contact window C1, and the second contact window C2 exposes a portion of the second drain block 118b. The conductive layer 140 is disposed in the second contact window C2, and the pixel electrode 130 is electrically connected to the second drain block 118b through the conductive layer 140.

In short, in this embodiment, the second contact window C2 is formed through the pixel electrode 130 and the protective layer 120 to expose a portion of the second drain block 118b, and the conductive layer 140 is formed in the second contact window C2. The pixel structure 100 having the open circuit is repaired by electrically connecting the pixel electrode 130 and the second drain block 118b. In addition to repairing the pixel structure 100 that has to be scrapped to form a repaired pixel structure 100a, the repair method can re-use the repaired pixel structure 100a, thereby improving the yield of the pixel structure 100a and reducing the overall manufacturing cost. Moreover, since the pixel structure is formed by using four masks in this embodiment, the number of masks can be used in this embodiment relative to the five mask processes to reduce manufacturing cost and process. time.

In summary, since the present invention uses a gray scale mask to fabricate a metal layer having a first drain block, a second drain block, and a source block, the semiconductor layer is overexposed when the photoresist is overexposed. When the opening of the gate insulating layer is exposed, and the first drain block loses its function, the second contact window can be formed to repair the conductive layer to electrically connect the pixel electrode to the second drain block. Prime structure. In this way, the pixel structure that needs to be scrapped can be repaired again. use. Therefore, the repair method of the pixel structure of the present invention can improve the yield of production and reduce the overall manufacturing cost, and the repaired pixel structure has better reliability. In addition, since the present invention uses a gray scale mask to fabricate a pixel structure, the number of use of the mask can be reduced to improve the process yield.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and any one of ordinary skill in the art can make some modifications and refinements without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

10‧‧‧Substrate

20‧‧‧ photoresist layer

20a‧‧‧ patterned photoresist layer

22‧‧‧through holes

24‧‧‧Blind hole

30‧‧‧ Grayscale mask

32‧‧‧Light transmission area

34‧‧‧ semi-transparent area

36‧‧‧ shading area

100‧‧‧ pixel structure

100a‧‧‧Repaired pixel structure

110‧‧‧Active components

112‧‧‧ gate

114‧‧‧Brake insulation

116‧‧‧Semiconductor layer

116a‧‧‧Channel layer

118‧‧‧metal layer

118a‧‧‧ First bungee block

118b‧‧‧Second bungee block

118c‧‧‧ source block

120‧‧‧Protective layer

130‧‧‧pixel electrodes

140‧‧‧ Conductive layer

C1‧‧‧ first contact window

C2‧‧‧ second contact window

S‧‧‧ openings

1A to 1K are schematic cross-sectional views showing a method of fabricating a pixel structure according to an embodiment of the present invention.

10‧‧‧Substrate

100a‧‧‧ pixel structure

110‧‧‧Active components

112‧‧‧ gate

114‧‧‧Brake insulation

116‧‧‧Semiconductor layer

116a‧‧‧Channel layer

118‧‧‧metal layer

118a‧‧‧ First bungee block

118b‧‧‧Second bungee block

118c‧‧‧ source block

120‧‧‧Protective layer

130‧‧‧pixel electrodes

140‧‧‧ Conductive layer

C1‧‧‧ first contact window

C2‧‧‧ second contact window

S‧‧‧ openings

Claims (10)

A pixel structure repairing method is suitable for repairing a pixel structure, the pixel structure is disposed on a substrate, and the pixel structure comprises an active component, a protective layer and a pixel electrode, and the active component comprises a gate a gate, an insulating layer, a semiconductor layer and a metal layer, wherein the gate is disposed on the substrate, the gate insulating layer is located between the semiconductor layer and the gate, the semiconductor layer has a channel region and an exposed Opening a portion of the opening of the gate insulating layer, the metal layer having a first drain block, a second drain block, and a source block, wherein the source block and the second drain block are located On both sides of the channel region, the source block is located between the first drain block and the second drain block, and the source block and the first drain block are located at the opening On the side, the protective layer covers the active component and is in direct contact with a portion of the gate insulating layer exposed by the opening, the protective layer has a first contact window, and the pixel electrode is disposed on the protective layer and transmits the The first contact window is electrically connected to the first drain block The repairing method includes: forming a second contact window penetrating the pixel electrode and the protective layer, wherein the second contact window exposes a portion of the second drain block; and forming a conductive layer on the second contact In the window, the pixel electrode is electrically connected to the second drain block through the conductive layer. The method for repairing a pixel structure according to claim 1, wherein the method of forming the second contact window comprises a laser cutting process. The method for repairing a pixel structure according to claim 1, wherein the method of forming the conductive layer comprises a local chemical vapor deposition film forming method. The method for repairing a pixel structure according to claim 3, wherein the material of the conductive layer comprises tungsten. The method for repairing a pixel structure according to claim 1, wherein the method of forming the conductive layer comprises welding the second drain through a fusion step Block. The method of repairing a pixel structure according to claim 5, wherein the fusing step comprises a laser welding process. A repaired pixel structure includes: an active device disposed on a substrate, comprising: a gate on the substrate; a gate insulating layer disposed on the substrate and covering the gate; a semiconductor layer Disposed on the gate insulating layer, and having a channel region and an opening exposing a portion of the gate insulating layer; and a metal layer disposed on the semiconductor layer and having a first drain block and a first a second drain block and a source block, wherein the source block and the second drain block are located on both sides of the channel region, and the source block is located in the first drain block and the Between the second drain blocks, the source block and the first drain block are located on both sides of the opening; a protective layer covering the active component and the portion exposed by the opening The gate insulating layer is in direct contact, the protective layer has a first contact window; a pixel electrode is disposed on the protective layer and has a second contact window penetrating the pixel electrode and the protective layer, wherein the pixel The electrode passes through the first contact window and the first drain block Connecting, the second contact window exposing a portion of the second drain block; and a conductive layer disposed in the second contact window, and the pixel electrode passes through the conductive layer and the second drain block Electrical connection. The repaired pixel structure as described in claim 7, wherein the conductive layer is made of tungsten. The repaired pixel structure according to claim 7, wherein the conductive layer is substantially the same material as the second drain block. A method for fabricating a pixel structure includes: sequentially forming a gate, a gate insulating layer, a semiconductor layer, and a metal layer on a substrate; forming a photoresist layer on the metal layer; and using a gray scale light Exposing the photoresist layer to the photoresist layer, wherein the gray scale mask has a light transmissive region, a half light transmissive region, and a light shielding region, wherein the light transmissive region is located between the semi-transmissive region and the light shielding region; The photoresist layer is then developed to form a patterned photoresist layer, wherein the patterned photoresist layer has a via exposing a portion of the metal layer and a blind via; the patterned photoresist layer is An etching mask removes a portion of the metal layer and a portion of the semiconductor layer exposed by the via, and the removed portion corresponds to the metal layer under the blind via and a portion of the semiconductor layer underneath the blind via, Forming an opening and a channel region exposing a portion of the gate insulating layer on the semiconductor layer, and dividing the metal layer into a first drain block, a second drain block, and a source block Where the source block and the second drain block are On both sides of the channel region, the source block is located between the first drain block and the second drain block, and the source block and the first drain block are located at the opening On both sides; removing the patterned photoresist layer; forming a protective layer on the substrate, wherein the protective layer has a first contact window, and the protective layer covers the metal layer and is exposed by the opening a portion of the gate insulating layer is in direct contact with each other; a pixel electrode is formed on the protective layer, wherein the pixel electrode is electrically connected to the first drain block through the first contact window; forming a through-pixel electrode and a second contact window of the protective layer, wherein The second contact window exposes a portion of the second drain block; and a conductive layer is formed in the second contact window, and the pixel electrode is electrically connected to the second drain block through the conductive layer.