KR100803165B1 - Reflective-transmissive type liquid crystal device and method of manufacturing the same - Google Patents

Abstract

A reflection-transmissive liquid crystal display device and a method of manufacturing the same are disclosed. A gate line including a gate line and a gate electrode extending in a first direction on the substrate and a data line extending in a second direction perpendicular to the first direction are formed in the same layer as the gate line. A gate insulating film and an active pattern are sequentially formed on the gate wiring, the data line, and the substrate. On the gate insulating layer, a source electrode overlapping the first region of the active pattern and extending a portion thereof to be a transparent electrode for the pixel electrode, and a drain electrode overlapping the second region of the active pattern are formed. An interlayer insulating film having a first contact hole exposing the source electrode and a second contact hole exposing the data line is formed on the source / drain electrode and the gate insulating film. A reflective electrode connected to the source electrode through the first contact hole and a data bridge wiring connected to the data line through the second contact hole are simultaneously formed on the interlayer insulating layer. The process can be simplified by reducing the number of masks from the conventional seven to five.

Description

Reflective-transmissive type liquid crystal device and method of manufacturing the same

1A and 1B are cross-sectional views illustrating a method of manufacturing a conventional reflective-transmissive liquid crystal display device.

2 is a cross-sectional view of a reflection-transmissive liquid crystal display device according to the present invention.

3 is a plan view of a reflection-transmissive liquid crystal display device according to the present invention.

4A to 4H are cross-sectional views illustrating a method of manufacturing the reflection-transmissive liquid crystal display shown in FIG. 2.

<Explanation of symbols for main parts of the drawings>

100: transparent substrate 102: gate line

102a: gate electrode 102b: data line

104: gate insulating film 106: active pattern

108: contact layer pattern 110a, 110b: source / drain electrode

110c: transparent electrode 112: interlayer insulating film

114: uneven part 116a, 116b, 116c: contact hole

118a: reflective electrode 118b: data bridge wiring

The present invention relates to a reflection-transmissive liquid crystal display device and a manufacturing method thereof, and more particularly, to a reflection-transmission liquid crystal display device and a method for manufacturing the same, which can reduce the manufacturing cost by simplifying the process.

In today's information society, the role of electronic display devices becomes more and more important, and various electronic display devices are widely used in various industrial fields.

In general, an electronic display device refers to a device that transmits various information to a human through vision. In other words, an electronic display device may be defined as an electronic device that converts electrical information signals output from various electronic devices into optical information signals that can be recognized by human eyes, and serves as a bridge that connects humans and electronic devices. It may be defined as.

In such an electronic display device, when an optical information signal is displayed by a light emitting phenomenon, it is called an emissive display device, and when a light modulation is displayed by reflection, scattering, or interference phenomenon, a light receiving display ( It is called a non-emissive display device. The light emitting display device, also called an active display device, includes a cathode ray tube (CRT), a plasma display panel (PDP), a light emitting diode (LED), and an electroluminescent display (electroluminescent display). display; ELD). In addition, the light receiving display device, which is a passive display device, includes a liquid crystal display (LCD), an electrochemical display (ECD), an electrophoretic image display (EPID), and the like.

Cathode ray tubes (CRTs) used in image display devices such as televisions and computer monitors occupy the highest share in terms of display quality and economy, but have many disadvantages such as heavy weight, large volume and high power consumption. .

However, due to the rapid progress of semiconductor technology, the electronic display device suitable for the new environment, that is, the thin and light, the low driving voltage and the low power consumption of the electronic device, according to the miniaturization, low voltage and low power of various electronic devices, and the miniaturization and light weight of the electronic device, The demand for flat panel display devices with features is rapidly increasing.

Among the various flat panel display devices currently developed, liquid crystal displays are thinner and lighter than other display devices, have low power consumption and low driving voltage, and are widely used in various electronic devices because they can display images close to cathode ray tubes. Is being used.

The liquid crystal display device is composed of two substrates having electrodes formed thereon and a liquid crystal layer inserted therebetween, by applying a voltage to the electrodes to rearrange liquid crystal molecules of the liquid crystal layer to control the amount of transmitted light. Display device. Electrodes are formed on each of the two substrates, and a thin film transistor (TFT) for switching a voltage applied to each electrode is formed on one of the two substrates.

Meanwhile, the liquid crystal display may be classified into a transmissive liquid crystal display displaying an image using an external light source and a reflective liquid crystal display using natural light instead of the external light source. In electronic devices such as clocks and calculators that require minimal power consumption, reflective liquid crystal displays are often used. However, transmissive liquid crystal displays are generally used in notebook computers that require high quality image display.

In the current trend, in order to realize the maximum high quality image while reducing the power consumption, it is possible to take advantage of both the reflection type and the transmission type to obtain the appropriate visibility for the use environment despite the change in the ambient light intensity. Reflective-transmissive liquid crystal display devices have been developed.

1A and 1B are cross-sectional views illustrating a method of manufacturing a conventional reflective-transmissive liquid crystal display device.

Referring to FIG. 1A, after depositing a first metal film for gate wiring on a transparent substrate 10 made of glass, quartz, or sapphire, the first metal film is patterned by a photolithography process using a first mask to form a gate electrode 12. ) And a gate line connected to the gate electrode 12 and including a gate line (not shown) extending in a first direction.

After depositing a silicon nitride film on the gate wiring and the substrate 10 to form a gate insulating film 16, an active layer consisting of an amorphous silicon film and an amorphous silicon film doped with n ⁺ on the gate insulating film 16 The contact layers thus formed are deposited one after the other. Subsequently, the contact layer and the active layer are patterned by a photolithography process using a second mask to form the contact layer pattern 18 and the active pattern 16. The contact layer pattern 18 is formed to form an ohmic contact between the active pattern 16 and the source / drain electrodes to be formed thereon.

A data line (not shown) for depositing a second metal film for data wiring on the entire surface of the resultant, and then patterning the second metal film in a photolithography process using the third mask to partition the pixel portion crossing the gate line; A data line including the source / drain electrodes 20a and 20b is formed. Subsequently, the contact layer 18 exposed using the third mask is removed by an etching process, thereby leaving only the active pattern 16 to be a channel region.

Spin-coating a photosensitive organic film on the entire surface of the resultant to form a first insulating film 22 serving as an interlayer insulating film and a protective film, and then exposing and developing the first insulating film 22 using a fourth mask. A first contact hole 24 exposing a portion of the source electrode 20a is formed. In this case, an embossing (not shown) is formed on the surface of the first insulating film 22 to make the reflecting plate of the pixel portion into a scattering structure.

After depositing a transparent conductive film such as indium-tin-oxide (ITO) or indium-zinc-oxide (IZO) provided as a transmission window and a pixel electrode on the first contact hole 24 and the first insulating film 22 The transparent conductive film is patterned by a photolithography process using a fifth mask. Then, the transparent electrode 26 connected to the source electrode 20a is formed through the first contact hole 24.

After forming the second insulating film 28 on the transparent electrode 26 and the first insulating film 22, the second insulating film 28 is etched by a photolithography process using a sixth mask to form the source electrode 20a. A second contact hole 29 exposing a portion of

After depositing a reflective conductive film such as aluminum (Al) or silver (Ag) provided as a reflector and a pixel electrode on the second contact hole 29 and the second insulating layer 28, a photolithography process using a seventh mask is performed. The reflective conductive film is then patterned. Then, the reflective electrode 30 connected to the source electrode 20a is formed through the second contact hole 29. At this time, the region where the reflective electrode 30 remains on the transparent electrode 26 becomes the reflecting plate R, and the region where only the transparent electrode 26 remains is the transmission window T.

According to the above-described conventional reflection-transmissive liquid crystal display device, in order to make the reflection-transmissive structure, the gate wiring, the active layer, the data wiring, the first contact hole, the transparent electrode, the second contact hole, and the reflection electrode in total of seven layers, 7 A photolithography process or an exposure process using a mask of a hawk is necessary.

In general, as the number of photographic processes increases, the process cost and the probability of process error increase, which increases the manufacturing cost. Therefore, the reflection-transmissive liquid crystal display can be manufactured with a simplified process of manufacturing a transmissive liquid crystal display. Technology development is urgently needed.

 Accordingly, it is a first object of the present invention to provide a reflection-transmissive liquid crystal display device which can simplify the process by reducing the number of masks.

It is a second object of the present invention to provide a method of manufacturing a reflection-transmissive liquid crystal display device which can simplify the process by reducing the number of masks.

In order to achieve the first object, the present invention, a gate wiring formed on a substrate, including a gate line extending in a first direction and a gate electrode connected to the gate line; A data line formed on the substrate in the same layer as the gate line and extending in a second direction perpendicular to the first direction; A gate insulating film formed on the gate wiring, the data line and the substrate; An active pattern formed on the gate insulating layer on the gate electrode; A source electrode formed on the gate insulating layer and overlapping a first region of the active pattern, a portion of which is extended to form a transparent electrode for a pixel electrode, and a second region opposite to the first region of the active pattern; A drain electrode; An interlayer insulating layer formed on the source / drain electrode and the gate insulating layer and having a first contact hole exposing the source electrode and a second contact hole exposing the data line; And a reflective electrode formed on the interlayer insulating layer and connected to the source electrode through the first contact hole, and a data bridge line connected to the data line through the second contact hole. A liquid crystal display device is provided.

In order to achieve the second object of the present invention, a gate line including a gate line extending in a first direction on a substrate and a gate electrode connected to the gate line, and a second direction perpendicular to the first direction Simultaneously forming data lines extending to the lines; Forming a gate insulating film on the entire surface of the resultant product; Forming an active pattern on a gate insulating film on the gate electrode; Forming a source electrode and a drain electrode overlapping both edges of the active pattern on the gate insulating layer, and simultaneously extending a portion of the source electrode to form a transparent electrode; Forming an interlayer insulating film on the entire surface of the resultant product; Forming a first contact hole exposing the source electrode and a second contact hole exposing the data line by removing the interlayer insulating film; And simultaneously forming a reflective electrode connected to the source electrode through the first contact hole and a data bridge wiring connected to the data line through the second contact hole on the interlayer insulating layer. A method of manufacturing a reflection-transmissive liquid crystal display device is provided.

According to the present invention, a source / drain electrode and a transparent electrode which can be used in the same material are formed at the same time. In addition, when the gate line is formed, the data lines for signal transmission are simultaneously formed, and when the reflective electrode is formed, the data bridge lines for connecting the data lines are simultaneously formed. Then, an image signal is transferred from the data line to the drain electrode through the data bridge wiring.

Therefore, since the number of masks can be reduced from the conventional seven to five, the manufacturing cost can be reduced by simplifying the process.

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

2 is a cross-sectional view of a reflection-transmissive liquid crystal display device according to the present invention, and FIG. 3 is a plan view of the reflection-transmission liquid crystal display device shown in FIG. 2. 2 is a cross-sectional view taken along line AA ′ of FIG. 3.

2 and 3, a gate wiring made of a metal film such as chromium (Cr), aluminum (Al), molybdenum (Mo), or molybdenum tungsten (MoW) is formed on the transparent substrate 100. The gate wiring includes a gate line 102 extending in a first direction (ie, a transverse direction) and a gate electrode 102a of a thin film transistor that is part of the gate line 102. In addition, the signal transmission data line 102b is formed long in the second direction (ie, the longitudinal direction) perpendicular to the gate line 102 at a predetermined distance from the gate line 102. The data lines 102b are formed together when the metal film for the gate wiring is patterned.

A gate insulating layer 104 made of an inorganic material, eg, silicon nitride, is formed on the gate line, the data line 102b and the substrate 100. On the gate insulating film 104 corresponding to the gate electrode 102a, an active pattern 106 made of a semiconductor film such as amorphous silicon and a contact layer pattern 108 made of an n ⁺ doped amorphous silicon film are sequentially stacked. .

A transparent conductive film is formed on the contact layer pattern 108 and the gate insulating layer 104, and the source electrode 110a overlapping the first region of the active pattern 106 and the active pattern 106 facing the first region. A drain electrode 110b overlapping with the second region of the second electrode is formed. The source electrode 110a is a transparent electrode 110c for a pixel electrode that is partially extended to receive an image signal from a thin film transistor to generate an electric field together with an electrode (not shown) of an upper substrate (ie, a color filter substrate). Is used. Therefore, the transparent electrode 110c is formed in the pixel portion partitioned by the gate line and the data line, and the edge thereof is formed to overlap the gate line and the data line in order to secure a high aperture ratio.

An interlayer insulating layer 112 made of a photosensitive organic material is formed on the source / drain electrodes 110a and 110b and the gate insulating layer 104. Concave-convex portions 114 are formed on some surfaces of the interlayer insulating layer 112 to increase reflection efficiency. The first contact hole 116a exposing the source electrode 110a through the interlayer insulating layer 112 and the second contact hole 116b exposing the data line 102b and the drain electrode 110b are exposed. Third contact holes 116c are formed at the same time.

On the interlayer insulating layer 112, a reflective electrode 118a connected to the source electrode 110a through a first contact hole 116a and provided as a reflector and a pixel electrode, and a data line through a second contact hole 116b. The data bridge wiring 118b connected to the 102b is formed at the same time. The data bridge wiring 118b connects the data line 102b and the drain electrode 110b through the second contact hole 116b and the third contact hole 116c. Therefore, the image signal input from the outside to the data line 102b is transmitted to the drain electrode 110b of the thin film transistor through the data bridge wiring 118b.

According to the present invention, the reflective electrode 118a is removed to expose the transparent electrode 110c below the transparent window.

4A to 4H are cross-sectional views illustrating a method of manufacturing the reflection-transmissive liquid crystal display shown in FIG. 2.

Referring to FIG. 4A, a metal film 101 such as chromium (Cr), aluminum (Al), molybdenum (Mo), or molybdenum tungsten (MoW) may be formed on a transparent substrate 100 made of an insulating material such as glass, quartz, or sapphire. E).

Referring to FIG. 4B, the metal layer 101 is patterned by a photolithography process using a first mask to form a gate line (reference numeral 102 of FIG. 3) and a pixel portion that extend in a first direction (ie, a transverse direction). A gate wiring is formed and includes a gate electrode 102a which is a part of the gate line 102. At the same time, a signal transmission data line 102b is formed which is spaced apart from the gate line 102 at a predetermined interval and extends in a direction perpendicular to the gate line 102. The data line 102b is connected to the data bridge wiring in a subsequent process to transfer an image signal to the drain electrode of the thin film transistor.

In this case, the gate line 102 may be formed to have an extended structure to form the expanded portion as a capacitor wiring.

Referring to FIG. 4C, a gate insulating film 104 made of an inorganic insulating film such as silicon nitride on the gate wiring, the data line 102b, and the substrate 100 is subjected to chemical vapor deposition (CVD). It is formed to a thickness of 4500Å.

Subsequently, a semiconductor film such as amorphous silicon is deposited on the gate insulating layer 104 by a CVD process to form an active layer 105. An n ⁺ doped amorphous silicon film is deposited on the active layer 105 by a CVD process to form a contact layer 107.

Referring to FIG. 4D, the contact layer 107 and the active layer 105 are patterned by a photolithography process using a second mask to form an active pattern 106 on the gate insulating layer 104 on the gate electrode 102a. And a contact layer pattern 108. The contact layer pattern 108 serves to lower the resistance by making an ohmic contact between the active pattern 106 and the source / drain electrodes to be formed thereon.

Subsequently, a transparent conductive film 109 such as ITO or IZO is deposited on the contact layer pattern 108 and the gate insulating film 104.

Referring to FIG. 4E, after the photoresist film is coated on the transparent conductive film 109, a photoresist pattern (not shown) is formed by performing exposure and development processes using a third mask. Subsequently, the transparent conductive layer 109 is dry-etched using the photoresist pattern as an etching mask to form source and drain electrodes 110a and 110b respectively overlapping both edges of the active pattern 108. do. In this case, a portion of the source electrode 110a is extended to form a transparent electrode 110c which is a pixel electrode.

Referring to FIG. 4F, the exposed contact layer pattern 108 is removed by dry etching using the photoresist pattern as an etching mask. Then, only the active pattern 106 to be the channel region remains.

After removing the photoresist pattern by an ashing and stripping process, a photosensitive organic material is coated on the entire surface of the resultant to form the interlayer insulating film 112.

Referring to FIG. 4G, the first contact hole 116a and the data line 102b exposing a portion of the source electrode 110a by exposing and developing the interlayer insulating layer 112 using a fourth mask. A third contact hole 116b for exposing the drain electrode 110b and a third contact hole 116c for exposing the drain electrode 110b are formed. At the same time, the uneven portion 114 is formed on the surface of the interlayer insulating layer 112 to make the reflective plate of the pixel portion into a scattering structure. The uneven portion 114 serves to improve the viewing angle by scattering light passing through the liquid crystal. Preferably, the uneven portion 114 is formed to have an inclination angle of 5 ° to 15 °.

Referring to FIG. 4H, a reflective conductive layer 117 having high reflectance such as aluminum (Al) or silver (Ag) is formed on the contact holes 116a, 116b, and 116c and the interlayer insulating layer 112.

Subsequently, the reflective conductive layer 117 is patterned by a photolithography process using a fifth mask to reflect the pixel electrode connected to the source electrode 110a through the first contact hole 116a as shown in FIG. 2. The electrode 118a is formed. Then, the reflective electrode 118a is removed to expose the transparent electrode 110c below the transparent window, and the remaining area except the transparent window is provided as a reflective plate.                     

When the reflective electrode 118a is formed, a data bridge line 118b connected to the data line 102b through the second contact hole 116b is formed at the same time. The data bridge wiring 118b connects the data line 102b and the drain electrode 110b through the second contact hole 116b and the third contact hole 116c. Therefore, the image signal input from the outside to the data line 102b is transmitted to the drain electrode 110b of the thin film transistor through the data bridge wiring 118b.

As described above, according to the present invention, a photolithography process or an exposure process is performed on a total of five layers of a gate wiring, an active layer, a source / drain electrode and a transparent electrode, a contact hole, and a reflective electrode to manufacture a reflection-transmissive liquid crystal display device. It is necessary. That is, data for simultaneously forming a source / drain electrode and a transparent electrode which can be used as the same material, simultaneously forming a signal transmission data line when forming a gate wiring, and data for connecting the data lines when forming a reflective electrode Bridge wiring is formed at the same time. Therefore, since the number of masks can be reduced from the conventional seven sheets to five sheets, cost reduction can be obtained by simplifying the process.

As described above, although described with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and modified within the scope of the present invention without departing from the spirit and scope of the present invention described in the claims below. It will be appreciated that it can be changed.

Claims (12)

A gate wiring formed on the substrate and including a gate line extending in a first direction and a gate electrode connected to the gate line; A data line formed on the substrate in the same layer as the gate line and extending in a second direction perpendicular to the first direction; A gate insulating film formed on the gate wiring, the data line and the substrate; An active pattern formed on the gate insulating layer on the gate electrode; A source electrode formed on the gate insulating layer and overlapping a first region of the active pattern and including a transparent electrode for a pixel electrode formed in a unit pixel, and a second region opposite to the first region of the active pattern; A drain electrode; An interlayer insulating layer formed on the source / drain electrode and the gate insulating layer and having a first contact hole exposing the source electrode and a second contact hole exposing the data line; And And a reflective electrode formed on the interlayer insulating layer and connected to the source electrode through the first contact hole, and a data bridge wiring connected to the data line through the second contact hole. Display. The reflection-transmissive liquid crystal display device according to claim 1, wherein the source / drain electrodes are formed of a transparent conductive film. The reflection-transmissive liquid crystal display device according to claim 1, wherein the gate line includes a capacitor wiring portion formed in the unit pixel and overlapping the transparent electrode. The liquid crystal display of claim 1, wherein the data bridge line connects the data line and the drain electrode through a third contact hole formed in the interlayer insulating layer over the second contact hole and the drain electrode. Display. Forming a gate line on the substrate, the gate line including a gate line extending in a first direction and a gate electrode connected to the gate line, and a data line extending in a second direction perpendicular to the first direction; Forming a gate insulating film on the substrate to cover the gate wiring and the data line; Forming an active pattern on a gate insulating film on the gate electrode; Forming a source electrode on the gate insulating layer, the source electrode including a transparent electrode for a pixel electrode overlapping one side of both edges of the active pattern and formed in a unit pixel, and a drain electrode overlapping the other side of the both edges; Forming an interlayer insulating film on the gate insulating film to cover the active pattern, the source electrode and the drain electrode; Etching the interlayer insulating film to form a first contact hole exposing the source electrode and a second contact hole exposing the data line; And And simultaneously forming a reflective electrode connected to the source electrode through the first contact hole and a data bridge wiring connected to the data line through the second contact hole on the interlayer insulating layer. -Manufacturing method of transmissive liquid crystal display device. The method of manufacturing a reflection-transmissive liquid crystal display device according to claim 5, wherein the source / drain electrodes are formed of a transparent conductive film. The method of claim 5, wherein in the forming of the gate wiring, And the gate line includes a capacitor wiring portion formed in the unit pixel and overlapping the transparent electrode. The method of claim 5, wherein in the forming of the first and second contact holes, a third contact hole exposing the drain electrode is simultaneously formed. 10. The method of claim 8, wherein the data bridge line is formed to connect the data line and the drain electrode through the second contact hole and the third contact hole. The method of manufacturing a reflection-transmissive liquid crystal display device according to claim 5, wherein the interlayer insulating film is formed of a photosensitive organic film. 12. The method of claim 10, wherein in the forming of the first and second contact holes, an uneven portion is formed on a surface of the interlayer insulating layer. The method of manufacturing a reflection-transmissive liquid crystal display device according to claim 11, wherein the uneven portion is formed to have an inclination angle of 5 degrees to 15 degrees.

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